diff --git a/fuzzers/.gitignore b/fuzzers/.gitignore
new file mode 100644
index 00000000..01a18a08
--- /dev/null
+++ b/fuzzers/.gitignore
@@ -0,0 +1,2 @@
+timing3.csv
+timing3.txt
diff --git a/fuzzers/007-timing/csv_group2flat.py b/fuzzers/007-timing/csv_group2flat.py
index 403b2991..da0251dd 100644
--- a/fuzzers/007-timing/csv_group2flat.py
+++ b/fuzzers/007-timing/csv_group2flat.py
@@ -6,51 +6,57 @@ from timfuz import Benchmark, loadc_Ads_bs, load_sub, Ads2bounds, corners2csv, c
 def gen_flat(fns_in, sub_json, corner=None):
     Ads, bs = loadc_Ads_bs(fns_in, ico=True)
     bounds = Ads2bounds(Ads, bs)
-    zeros = set()
+    # Elements with zero delay assigned due to sub group
+    group_zeros = set()
+    # Elements with a concrete delay
     nonzeros = set()
 
+    if corner:
+        zero_row = [None, None, None, None]
+        zero_row[corner_s2i[corner]] = 0
+    else:
+        zero_row = None
+
     for bound_name, bound_bs in bounds.items():
         sub = sub_json['subs'].get(bound_name, None)
-        if sub:
+        if bound_name in sub_json['zero_names']:
+            if zero_row:
+                yield bound_name, 0
+        elif sub:
+            print('sub', sub)
             # put entire delay into pivot
             pivot = sub_json['pivots'][bound_name]
-            assert pivot not in zeros
+            assert pivot not in group_zeros
             nonzeros.add(pivot)
             non_pivot = set(sub.keys() - set([pivot]))
             #for name in non_pivot:
             #    assert name not in nonzeros, (pivot, name, nonzeros)
-            zeros.update(non_pivot)
+            group_zeros.update(non_pivot)
             yield pivot, bound_bs
         else:
             nonzeros.add(bound_name)
             yield bound_name, bound_bs
     # non-pivots can appear multiple times, but they should always be zero
     # however, due to substitution limitations, just warn
-    violations = zeros.intersection(nonzeros)
+    violations = group_zeros.intersection(nonzeros)
     if len(violations):
         print('WARNING: %s non-0 non-pivot' % (len(violations)))
 
     # XXX: how to best handle these?
     # should they be fixed 0?
-    if corner:
-        zero_row = [None, None, None, None]
-        zero_row[corner_s2i[corner]] = 0
-        for zero in zeros - violations:
+    if zero_row:
+        print('zero_row', len(group_zeros), len(violations))
+        for zero in sub_json['zero_names']:
+            yield zero, zero_row
+        for zero in group_zeros - violations:
             yield zero, zero_row
 
 
-def run(fns_in, fnout, sub_json, corner=None, sort=False, verbose=False):
-    '''
-    if sort:
-        sortf = sorted
-    else:
-        sortf = lambda x: x
-    '''
-
+def run(fns_in, fnout, sub_json, corner=None, verbose=False):
     with open(fnout, 'w') as fout:
         fout.write('ico,fast_max fast_min slow_max slow_min,rows...\n')
-        #for name, corners in sortf(gen_flat(fnin, sub_json)):
-        for name, corners in gen_flat(fns_in, sub_json, corner=corner):
+        for name, corners in sorted(list(gen_flat(fns_in, sub_json,
+                                                  corner=corner))):
             row_ico = 1
             items = [str(row_ico), corners2csv(corners)]
             items.append('%u %s' % (1, name))
@@ -64,7 +70,6 @@ def main():
         description='Substitute .csv to ungroup correlated variables')
 
     parser.add_argument('--verbose', action='store_true', help='')
-    #parser.add_argument('--sort', action='store_true', help='')
     parser.add_argument('--sub-csv', help='')
     parser.add_argument(
         '--sub-json',
@@ -87,7 +92,6 @@ def main():
             args.fns_in,
             args.out,
             sub_json=sub_json,
-            #sort=args.sort,
             verbose=args.verbose,
             corner=args.corner)
     finally:
diff --git a/fuzzers/007-timing/projects/corner.mk b/fuzzers/007-timing/projects/corner.mk
index f332d727..1bfa8d6b 100644
--- a/fuzzers/007-timing/projects/corner.mk
+++ b/fuzzers/007-timing/projects/corner.mk
@@ -32,7 +32,7 @@ build/$(CORNER)/leastsq.csv: build/sub.json build/grouped.csv build/checksub bui
 
 build/$(CORNER)/linprog.csv: build/$(CORNER)/leastsq.csv build/grouped.csv
 	# Tweak rough timing model, making sure all constraints are satisfied
-	ALLOW_ZERO_EQN=$(ALLOW_ZERO_EQN) python3 $(TIMFUZ_DIR)/solve_linprog.py --sub-json build/sub.json --sub-csv build/$(CORNER)/leastsq.csv --massage build/grouped.csv --corner $(CORNER) --out build/$(CORNER)/linprog.csv.tmp
+	ALLOW_ZERO_EQN=$(ALLOW_ZERO_EQN) python3 $(TIMFUZ_DIR)/solve_linprog.py --sub-json build/sub.json --bounds-csv build/$(CORNER)/leastsq.csv --massage build/grouped.csv --corner $(CORNER) --out build/$(CORNER)/linprog.csv.tmp
 	mv build/$(CORNER)/linprog.csv.tmp build/$(CORNER)/linprog.csv
 
 build/$(CORNER)/flat.csv: build/$(CORNER)/linprog.csv
diff --git a/fuzzers/007-timing/rref.py b/fuzzers/007-timing/rref.py
index fedcfef5..be13c805 100644
--- a/fuzzers/007-timing/rref.py
+++ b/fuzzers/007-timing/rref.py
@@ -1,6 +1,6 @@
 #!/usr/bin/env python3
 
-from timfuz import Benchmark, Ar_di2np, loadc_Ads_b, index_names, A_ds2np, simplify_rows
+from timfuz import Benchmark, Ar_di2np, loadc_Ads_b, index_names, A_ds2np, simplify_rows, OrderedSet
 import numpy as np
 import glob
 import math
@@ -10,6 +10,22 @@ from collections import OrderedDict
 from fractions import Fraction
 
 
+def rm_zero_cols(Ads, verbose=True):
+    removed = OrderedSet()
+
+    print('Removing ZERO elements')
+    for row_ds in Ads:
+        for k in set(row_ds.keys()):
+            if k in removed:
+                del row_ds[k]
+            elif k.find('ZERO') >= 0:
+                del row_ds[k]
+                removed.add(k)
+                if verbose:
+                    print('  Removing %s' % k)
+    return removed
+
+
 def fracr_quick(r):
     return [Fraction(numerator=int(x), denominator=1) for x in r]
 
@@ -22,19 +38,20 @@ def fracm_quick(m):
 
 
 class State(object):
-    def __init__(self, Ads, drop_names=[]):
+    def __init__(self, Ads, zero_names=[]):
         self.Ads = Ads
         self.names = index_names(self.Ads)
 
         # known zero delay elements
-        self.drop_names = set(drop_names)
+        self.zero_names = OrderedSet(zero_names)
         # active names in rows
         # includes sub variables, excludes variables that have been substituted out
-        self.base_names = set(self.names)
+        self.base_names = OrderedSet(self.names)
+        #self.names = OrderedSet(self.base_names)
         self.names = set(self.base_names)
         # List of variable substitutions
         # k => dict of v:n entries that it came from
-        self.subs = {}
+        self.subs = OrderedDict()
         self.verbose = True
 
     def print_stats(self):
@@ -45,51 +62,44 @@ class State(object):
                 "    Largest: %u" % max([len(x) for x in self.subs.values()]))
         print("  Rows: %u" % len(self.Ads))
         print(
-            "  Cols (in): %u" % (len(self.base_names) + len(self.drop_names)))
+            "  Cols (in): %u" % (len(self.base_names) + len(self.zero_names)))
         print("  Cols (preprocessed): %u" % len(self.base_names))
-        print("    Drop names: %u" % len(self.drop_names))
+        print("    ZERO names: %u" % len(self.zero_names))
         print("  Cols (out): %u" % len(self.names))
         print("  Solvable vars: %u" % len(self.names & self.base_names))
         assert len(self.names) >= len(self.subs)
 
     @staticmethod
-    def load(fn_ins, simplify=False, corner=None):
+    def load(fn_ins, simplify=False, corner=None, rm_zero=False):
+        zero_names = OrderedSet()
+
         Ads, b = loadc_Ads_b(fn_ins, corner=corner, ico=True)
+        if rm_zero:
+            zero_names = rm_zero_cols(Ads)
         if simplify:
             print('Simplifying corner %s' % (corner, ))
             Ads, b = simplify_rows(Ads, b, remove_zd=False, corner=corner)
-        return State(Ads)
+        return State(Ads, zero_names=zero_names)
 
 
 def write_state(state, fout):
     j = {
-        'names': dict([(x, None) for x in state.names]),
-        'drop_names': list(state.drop_names),
-        'base_names': list(state.base_names),
-        'subs': dict([(name, values) for name, values in state.subs.items()]),
-        'pivots': state.pivots,
+        'names':
+        OrderedDict([(x, None) for x in state.names]),
+        'zero_names':
+        sorted(list(state.zero_names)),
+        'base_names':
+        sorted(list(state.base_names)),
+        'subs':
+        OrderedDict([(name, values) for name, values in state.subs.items()]),
+        'pivots':
+        state.pivots,
     }
     json.dump(j, fout, sort_keys=True, indent=4, separators=(',', ': '))
 
 
-def Anp2matrix(Anp):
-    '''
-    Original idea was to make into a square matrix
-    but this loses too much information
-    so now this actually isn't doing anything and should probably be eliminated
-    '''
-
-    ncols = len(Anp[0])
-    A_ub2 = [np.zeros(ncols) for _i in range(ncols)]
-    dst_rowi = 0
-    for rownp in Anp:
-        A_ub2[dst_rowi] = np.add(A_ub2[dst_rowi], rownp)
-        dst_rowi = (dst_rowi + 1) % ncols
-    return A_ub2
-
-
 def row_np2ds(rownp, names):
-    ret = {}
+    ret = OrderedDict()
     assert len(rownp) == len(names), (len(rownp), len(names))
     for namei, name in enumerate(names):
         v = rownp[namei]
@@ -102,7 +112,7 @@ def row_sym2dsf(rowsym, names):
     '''Convert a sympy row into a dictionary of keys to (numerator, denominator) tuples'''
     from sympy import fraction
 
-    ret = {}
+    ret = OrderedDict()
     assert len(rowsym) == len(names), (len(rowsym), len(names))
     for namei, name in enumerate(names):
         v = rowsym[namei]
@@ -117,11 +127,7 @@ def state_rref(state, verbose=False):
     names, Anp = A_ds2np(state.Ads)
 
     print('np: %u rows x %u cols' % (len(Anp), len(Anp[0])))
-    if 0:
-        print('Combining rows into matrix')
-        mnp = Anp2matrix(Anp)
-    else:
-        mnp = Anp
+    mnp = Anp
     print('Matrix: %u rows x %u cols' % (len(mnp), len(mnp[0])))
     print('Converting np to sympy matrix')
     mfrac = fracm_quick(mnp)
@@ -145,7 +151,7 @@ def state_rref(state, verbose=False):
         print('rref')
         sympy.pprint(rref)
 
-    state.pivots = {}
+    state.pivots = OrderedDict()
 
     def row_solved(rowsym, row_pivot):
         for ci, c in enumerate(rowsym):
@@ -177,7 +183,7 @@ def state_rref(state, verbose=False):
         state.names.add(group_name)
         # Remove substituted variables
         # Note: variables may appear multiple times
-        state.names.difference_update(set(rowdsf.keys()))
+        state.names.difference_update(OrderedSet(rowdsf.keys()))
         pivot_name = names[row_pivot]
         state.pivots[group_name] = pivot_name
         if verbose:
@@ -186,11 +192,12 @@ def state_rref(state, verbose=False):
     return state
 
 
-def run(fnout, fn_ins, simplify=False, corner=None, verbose=0):
+def run(fnout, fn_ins, simplify=False, corner=None, rm_zero=False, verbose=0):
     print('Loading data')
 
     assert len(fn_ins) > 0
-    state = State.load(fn_ins, simplify=simplify, corner=corner)
+    state = State.load(
+        fn_ins, simplify=simplify, corner=corner, rm_zero=rm_zero)
     state_rref(state, verbose=verbose)
     state.print_stats()
     if fnout:
@@ -209,6 +216,8 @@ def main():
     parser.add_argument('--verbose', action='store_true', help='')
     parser.add_argument('--simplify', action='store_true', help='')
     parser.add_argument('--corner', default="slow_max", help='')
+    parser.add_argument(
+        '--rm-zero', action='store_true', help='Remove ZERO elements')
     parser.add_argument(
         '--speed-json',
         default='build_speed/speed.json',
@@ -228,6 +237,7 @@ def main():
             fn_ins=fns_in,
             simplify=args.simplify,
             corner=args.corner,
+            rm_zero=args.rm_zero,
             verbose=args.verbose)
     finally:
         print('Exiting after %s' % bench)
diff --git a/fuzzers/007-timing/solve_leastsq.py b/fuzzers/007-timing/solve_leastsq.py
index db22b168..953c4dcf 100644
--- a/fuzzers/007-timing/solve_leastsq.py
+++ b/fuzzers/007-timing/solve_leastsq.py
@@ -30,47 +30,6 @@ def mkestimate(Anp, b):
     return x0
 
 
-def save(outfn, xvals, names, corner):
-    # ballpark minimum actual observed delay is around 7 (carry chain)
-    # anything less than one is probably a solver artifact
-    delta = 0.5
-    corneri = corner_s2i[corner]
-
-    # Round conservatively
-    roundf = {
-        'fast_max': math.ceil,
-        'fast_min': math.floor,
-        'slow_max': math.ceil,
-        'slow_min': math.floor,
-    }[corner]
-
-    print('Writing results')
-    skips = 0
-    keeps = 0
-    with open(outfn, 'w') as fout:
-        # write as one variable per line
-        # this natively forms a bound if fed into linprog solver
-        fout.write('ico,fast_max fast_min slow_max slow_min,rows...\n')
-        for xval, name in zip(xvals, names):
-            row_ico = 1
-
-            # also review ceil vs floor choice for min vs max
-            # lets be more conservative for now
-            if xval < delta:
-                #print('Skipping %s: %0.6f' % (name, xval))
-                skips += 1
-                continue
-            keeps += 1
-            #xvali = round(xval)
-
-            items = [str(row_ico), acorner2csv(roundf(xval), corneri)]
-            items.append('%u %s' % (1, name))
-            fout.write(','.join(items) + '\n')
-    print(
-        'Wrote: skip %u => %u / %u valid delays' % (skips, keeps, len(names)))
-    assert keeps, 'Failed to estimate delay'
-
-
 def run_corner(
         Anp, b, names, corner, verbose=False, opts={}, meta={}, outfn=None):
     # Given timing scores for above delays (-ps)
@@ -140,7 +99,7 @@ def run_corner(
     print('Done')
 
     if outfn:
-        save(outfn, res.x, names, corner)
+        timfuz_solve.solve_save(outfn, res.x, names, corner, verbose=verbose)
 
 
 def main():
diff --git a/fuzzers/007-timing/solve_linprog.py b/fuzzers/007-timing/solve_linprog.py
index d22e14d1..0bb0dd6f 100644
--- a/fuzzers/007-timing/solve_linprog.py
+++ b/fuzzers/007-timing/solve_linprog.py
@@ -12,50 +12,12 @@ import time
 import timfuz_solve
 
 
-def save(outfn, xvals, names, corner):
-    # ballpark minimum actual observed delay is around 7 (carry chain)
-    # anything less than one is probably a solver artifact
-    delta = 0.5
-    corneri = corner_s2i[corner]
-
-    roundf = {
-        'fast_max': math.ceil,
-        'fast_min': math.floor,
-        'slow_max': math.ceil,
-        'slow_min': math.floor,
-    }[corner]
-
-    print('Writing results')
-    zeros = 0
-    with open(outfn, 'w') as fout:
-        # write as one variable per line
-        # this natively forms a bound if fed into linprog solver
-        fout.write('ico,fast_max fast_min slow_max slow_min,rows...\n')
-        for xval, name in zip(xvals, names):
-            row_ico = 1
-
-            # FIXME: only report for the given corner?
-            # also review ceil vs floor choice for min vs max
-            # lets be more conservative for now
-            if xval < delta:
-                print('WARNING: near 0 delay on %s: %0.6f' % (name, xval))
-                zeros += 1
-                #continue
-            items = [str(row_ico), acorner2csv(roundf(xval), corneri)]
-            items.append('%u %s' % (1, name))
-            fout.write(','.join(items) + '\n')
-    nonzeros = len(names) - zeros
-    print(
-        'Wrote: %u / %u constrained delays, %u zeros' %
-        (nonzeros, len(names), zeros))
-
-
 def run_corner(
         Anp, b, names, corner, verbose=False, opts={}, meta={}, outfn=None):
     if len(Anp) == 0:
         print('WARNING: zero equations')
         if outfn:
-            save(outfn, [], [], corner)
+            timfuz_solve.solve_save(outfn, [], [], corner)
         return
     maxcorner = {
         'slow_max': True,
@@ -180,7 +142,8 @@ def run_corner(
         print('Delay on %d / %d' % (nonzeros, len(res.x)))
 
         if outfn:
-            save(outfn, res.x, names, corner)
+            timfuz_solve.solve_save(
+                outfn, res.x, names, corner, verbose=verbose)
 
 
 def main():
@@ -192,7 +155,8 @@ def main():
 
     parser.add_argument('--verbose', action='store_true', help='')
     parser.add_argument('--massage', action='store_true', help='')
-    parser.add_argument('--sub-csv', help='')
+    parser.add_argument(
+        '--bounds-csv', help='Previous solve result starting point')
     parser.add_argument(
         '--sub-json', help='Group substitutions to make fully ranked')
     parser.add_argument('--corner', required=True, default="slow_max", help='')
@@ -215,7 +179,7 @@ def main():
         timfuz_solve.run(
             run_corner=run_corner,
             sub_json=sub_json,
-            sub_csv=args.sub_csv,
+            bounds_csv=args.bounds_csv,
             fns_in=fns_in,
             corner=args.corner,
             massage=args.massage,
diff --git a/fuzzers/007-timing/solve_qor.py b/fuzzers/007-timing/solve_qor.py
new file mode 100644
index 00000000..d3bb1eea
--- /dev/null
+++ b/fuzzers/007-timing/solve_qor.py
@@ -0,0 +1,60 @@
+#!/usr/bin/env python3
+
+from timfuz import Benchmark, load_sub, load_bounds, loadc_Ads_b
+import numpy as np
+
+
+def run(fns_in, corner, bounds_csv, verbose=False):
+    print('Loading data')
+    Ads, borig = loadc_Ads_b(fns_in, corner, ico=True)
+
+    bounds = load_bounds(bounds_csv, corner)
+    # verify is flattened
+    for k in bounds.keys():
+        assert 'GROUP_' not in k, 'Must operate on flattened bounds'
+
+    # compute our timing model delay at the given corner
+    bgots = []
+    for row_ds in Ads:
+        delays = [n * bounds[x] for x, n in row_ds.items()]
+        bgots.append(sum(delays))
+
+    ses = (np.asarray(bgots) - np.asarray(borig))**2
+    mse = (ses).mean(axis=None)
+    print('MSE aggregate: %0.1f' % mse)
+    print('Min SE: %0.1f' % min(ses))
+    print('Max SE: %0.1f' % max(ses))
+
+
+def main():
+    import argparse
+
+    parser = argparse.ArgumentParser(description='Report a timing fit score')
+
+    parser.add_argument('--verbose', action='store_true', help='')
+    parser.add_argument('--corner', required=True, default="slow_max", help='')
+    parser.add_argument(
+        '--bounds-csv',
+        required=True,
+        help='Previous solve result starting point')
+    parser.add_argument('fns_in', nargs='+', help='timing3.csv input files')
+    args = parser.parse_args()
+    # Store options in dict to ease passing through functions
+    bench = Benchmark()
+
+    fns_in = args.fns_in
+    if not fns_in:
+        fns_in = glob.glob('specimen_*/timing3.csv')
+
+    try:
+        run(
+            fns_in=fns_in,
+            corner=args.corner,
+            bounds_csv=args.bounds_csv,
+            verbose=args.verbose)
+    finally:
+        print('Exiting after %s' % bench)
+
+
+if __name__ == '__main__':
+    main()
diff --git a/fuzzers/007-timing/test_unique/.gitignore b/fuzzers/007-timing/test_unique/.gitignore
new file mode 100644
index 00000000..374eddc2
--- /dev/null
+++ b/fuzzers/007-timing/test_unique/.gitignore
@@ -0,0 +1,3 @@
+specimen_*
+build
+
diff --git a/fuzzers/007-timing/test_unique/Makefile b/fuzzers/007-timing/test_unique/Makefile
new file mode 100644
index 00000000..f7dca553
--- /dev/null
+++ b/fuzzers/007-timing/test_unique/Makefile
@@ -0,0 +1,22 @@
+N := 1
+SPECIMENS := $(addprefix specimen_,$(shell seq -f '%03.0f' $(N)))
+SPECIMENS_OK := $(addsuffix /OK,$(SPECIMENS))
+
+all: $(SPECIMENS_OK)
+
+$(SPECIMENS_OK):
+	bash generate.sh $(subst /OK,,$@) || (if [ "$(BADPRJ_OK)" != 'Y' ] ; then exit 1; fi; exit 0)
+	touch $@
+
+run:
+	$(MAKE) clean
+	$(MAKE) all
+	touch run.ok
+
+clean:
+	rm -rf specimen_[0-9][0-9][0-9]/ seg_clblx.segbits __pycache__ run.ok
+	rm -rf vivado*.log vivado_*.str vivado*.jou design *.bits *.dcp *.bit
+	rm -rf build
+
+.PHONY: all run clean
+
diff --git a/fuzzers/007-timing/test_unique/README.md b/fuzzers/007-timing/test_unique/README.md
new file mode 100644
index 00000000..84c19977
--- /dev/null
+++ b/fuzzers/007-timing/test_unique/README.md
@@ -0,0 +1,11 @@
+Characterizes how attributes vary across pips, wires, and nodes. Usage:
+
+```
+$ make
+$ python3 pip_unique.py
+$ python3 wire_unique.py
+$ python3 node_unique.py
+```
+
+NOTE: "make" will take a long time (about 2.5 hours on my machine)
+
diff --git a/fuzzers/007-timing/test_unique/generate.sh b/fuzzers/007-timing/test_unique/generate.sh
new file mode 100755
index 00000000..76583ac2
--- /dev/null
+++ b/fuzzers/007-timing/test_unique/generate.sh
@@ -0,0 +1,9 @@
+#!/bin/bash
+
+set -ex
+
+source ${XRAY_GENHEADER}
+TIMFUZ_DIR=$XRAY_DIR/fuzzers/007-timing
+
+vivado -mode batch -source ../generate.tcl
+
diff --git a/fuzzers/007-timing/test_unique/generate.tcl b/fuzzers/007-timing/test_unique/generate.tcl
new file mode 100644
index 00000000..99fd39d0
--- /dev/null
+++ b/fuzzers/007-timing/test_unique/generate.tcl
@@ -0,0 +1,97 @@
+source ../../../../utils/utils.tcl
+
+proc build_design {} {
+    create_project -force -part $::env(XRAY_PART) design design
+    read_verilog ../../src/picorv32.v
+    read_verilog ../top.v
+    synth_design -top top
+
+    puts "Locking pins"
+    set_property LOCK_PINS {I0:A1 I1:A2 I2:A3 I3:A4 I4:A5 I5:A6} \
+		[get_cells -quiet -filter {REF_NAME == LUT6} -hierarchical]
+
+    puts "Package stuff"
+    set_property -dict "PACKAGE_PIN $::env(XRAY_PIN_00) IOSTANDARD LVCMOS33" [get_ports clk]
+    set_property -dict "PACKAGE_PIN $::env(XRAY_PIN_01) IOSTANDARD LVCMOS33" [get_ports stb]
+    set_property -dict "PACKAGE_PIN $::env(XRAY_PIN_02) IOSTANDARD LVCMOS33" [get_ports di]
+    set_property -dict "PACKAGE_PIN $::env(XRAY_PIN_03) IOSTANDARD LVCMOS33" [get_ports do]
+
+    puts "pblocking"
+    create_pblock roi
+    set roipb [get_pblocks roi]
+    set_property EXCLUDE_PLACEMENT 1 $roipb
+    add_cells_to_pblock $roipb [get_cells roi]
+    resize_pblock $roipb -add "$::env(XRAY_ROI)"
+
+    puts "randplace"
+    randplace_pblock 50 roi
+
+    set_property CFGBVS VCCO [current_design]
+    set_property CONFIG_VOLTAGE 3.3 [current_design]
+    set_property BITSTREAM.GENERAL.PERFRAMECRC YES [current_design]
+
+    puts "dedicated route"
+    set_property CLOCK_DEDICATED_ROUTE FALSE [get_nets clk_IBUF]
+
+    place_design
+    route_design
+
+    write_checkpoint -force design.dcp
+    # disable combinitorial loop
+    # set_property IS_ENABLED 0 [get_drc_checks {LUTLP-1}]
+    #write_bitstream -force design.bit
+}
+
+proc pips_all {} {
+    set outdir "."
+    set fp [open "$outdir/pip_all.txt" w]
+    set items [get_pips]
+    puts "Items: [llength $items]"
+
+    set needspace 0
+    set properties [list_property [lindex $items 0]]
+    foreach item $items {
+        set needspace 0
+        foreach property $properties {
+            set val [get_property $property $item]
+            if {"$val" ne ""} {
+                if $needspace {
+                    puts -nonewline $fp " "
+                }
+                puts -nonewline $fp "$property:$val"
+                set needspace 1
+            }
+        }
+        puts $fp ""
+    }
+    close $fp
+}
+proc wires_all {} {
+    set outdir "."
+    set fp [open "$outdir/wire_all.txt" w]
+    set items [get_wires]
+    puts "Items: [llength $items]"
+
+    set needspace 0
+    set properties [list_property [lindex $items 0]]
+    foreach item $items {
+        set needspace 0
+        foreach property $properties {
+            set val [get_property $property $item]
+            if {"$val" ne ""} {
+                if $needspace {
+                    puts -nonewline $fp " "
+                }
+                puts -nonewline $fp "$property:$val"
+                set needspace 1
+            }
+        }
+        puts $fp ""
+    }
+    close $fp
+}
+
+build_design
+pips_all
+wires_all
+
diff --git a/minitests/timfuz/node_unique.py b/fuzzers/007-timing/test_unique/node_unique.py
similarity index 86%
rename from minitests/timfuz/node_unique.py
rename to fuzzers/007-timing/test_unique/node_unique.py
index 4a0630e7..df6cd0db 100644
--- a/minitests/timfuz/node_unique.py
+++ b/fuzzers/007-timing/test_unique/node_unique.py
@@ -1,3 +1,5 @@
+#!/usr/bin/env python3
+
 import re
 
 
@@ -40,8 +42,8 @@ def run(node_fin, verbose=0):
             return anode['wname']
             #return (anode['tile_type'], anode['wname'])
 
-        if nodei % 1000 == 0:
-            print 'Check node %d' % nodei
+        if nodei % 100000 == 0:
+            print('Check node %d, %u node types' % (nodei, len(refnodes)))
         # Existing node?
         try:
             refnode = refnodes[getk(anode)]
@@ -62,10 +64,10 @@ def run(node_fin, verbose=0):
             if k in refnode and k in anode:
 
                 def fail():
-                    print 'Mismatch on %s' % k
-                    print refnode[k], anode[k]
-                    print refnode['l']
-                    print anode['l']
+                    print('Mismatch on %s' % k)
+                    print(refnode[k], anode[k])
+                    print(refnode['l'])
+                    print(anode['l'])
                     #assert 0
 
                 if k == 'SPEED_CLASS':
@@ -97,6 +99,9 @@ if __name__ == '__main__':
 
     parser.add_argument('--verbose', type=int, help='')
     parser.add_argument(
-        'node_fn_in', default='/dev/stdin', nargs='?', help='Input file')
+        'node_fn_in',
+        default='specimen_001/wire_all.txt',
+        nargs='?',
+        help='Input file')
     args = parser.parse_args()
     run(open(args.node_fn_in, 'r'), verbose=args.verbose)
diff --git a/minitests/timfuz/perf_test.py b/fuzzers/007-timing/test_unique/perf_test.py
similarity index 100%
rename from minitests/timfuz/perf_test.py
rename to fuzzers/007-timing/test_unique/perf_test.py
diff --git a/minitests/timfuz/pip_unique.py b/fuzzers/007-timing/test_unique/pip_unique.py
similarity index 81%
rename from minitests/timfuz/pip_unique.py
rename to fuzzers/007-timing/test_unique/pip_unique.py
index f49cb1ca..c64c1744 100644
--- a/minitests/timfuz/pip_unique.py
+++ b/fuzzers/007-timing/test_unique/pip_unique.py
@@ -1,3 +1,5 @@
+#!/usr/bin/env python3
+
 import re
 
 
@@ -29,8 +31,8 @@ def run(node_fin, verbose=0):
             return anode['wname']
             return (anode['tile_type'], anode['wname'])
 
-        if nodei % 1000 == 0:
-            print 'Check node %d' % nodei
+        if nodei % 100000 == 0:
+            print('Check node %d, %u node types' % (nodei, len(refnodes)))
         # Existing node?
         try:
             refnode = refnodes[getk(anode)]
@@ -56,14 +58,14 @@ def run(node_fin, verbose=0):
             if k in refnode and k in anode:
 
                 def fail():
-                    print 'Mismatch on %s' % k
-                    print refnode[k], anode[k]
-                    print refnode['l']
-                    print anode['l']
+                    print('Mismatch on %s' % k)
+                    print(refnode[k], anode[k])
+                    print(refnode['l'])
+                    print(anode['l'])
                     #assert 0
 
                 if refnode[k] != anode[k]:
-                    print
+                    print('')
                     fail()
             # A key in one but not the other?
             elif k in refnode or k in anode:
@@ -81,6 +83,9 @@ if __name__ == '__main__':
 
     parser.add_argument('--verbose', type=int, help='')
     parser.add_argument(
-        'node_fn_in', default='/dev/stdin', nargs='?', help='Input file')
+        'node_fn_in',
+        default='specimen_001/pip_all.txt',
+        nargs='?',
+        help='Input file')
     args = parser.parse_args()
     run(open(args.node_fn_in, 'r'), verbose=args.verbose)
diff --git a/fuzzers/007-timing/test_unique/top.v b/fuzzers/007-timing/test_unique/top.v
new file mode 100644
index 00000000..0cb9b8a3
--- /dev/null
+++ b/fuzzers/007-timing/test_unique/top.v
@@ -0,0 +1,109 @@
+//move some stuff to minitests/ncy0
+
+`define SEED 32'h12345678
+
+module top(input clk, stb, di, output do);
+	localparam integer DIN_N = 42;
+	localparam integer DOUT_N = 79;
+
+	reg [DIN_N-1:0] din;
+	wire [DOUT_N-1:0] dout;
+
+	reg [DIN_N-1:0] din_shr;
+	reg [DOUT_N-1:0] dout_shr;
+
+	always @(posedge clk) begin
+		din_shr <= {din_shr, di};
+		dout_shr <= {dout_shr, din_shr[DIN_N-1]};
+		if (stb) begin
+			din <= din_shr;
+			dout_shr <= dout;
+		end
+	end
+
+	assign do = dout_shr[DOUT_N-1];
+
+	roi #(.DIN_N(DIN_N), .DOUT_N(DOUT_N))
+	    roi (
+		.clk(clk),
+		.din(din),
+		.dout(dout)
+	);
+endmodule
+
+module roi(input clk, input [DIN_N-1:0] din, output [DOUT_N-1:0] dout);
+	parameter integer DIN_N = -1;
+	parameter integer DOUT_N = -1;
+
+    /*
+    //Take out for now to make sure LUTs are more predictable
+	picorv32 picorv32 (
+		.clk(clk),
+		.resetn(din[0]),
+		.mem_valid(dout[0]),
+		.mem_instr(dout[1]),
+		.mem_ready(din[1]),
+		.mem_addr(dout[33:2]),
+		.mem_wdata(dout[66:34]),
+		.mem_wstrb(dout[70:67]),
+		.mem_rdata(din[33:2])
+	);
+	*/
+
+    /*
+	randluts randluts (
+		.din(din[41:34]),
+		.dout(dout[78:71])
+	);
+	*/
+	randluts #(.N(150)) randluts (
+		.din(din[41:34]),
+		.dout(dout[78:71])
+	);
+endmodule
+
+module randluts(input [7:0] din, output [7:0] dout);
+	parameter integer N = 250;
+
+	function [31:0] xorshift32(input [31:0] xorin);
+		begin
+			xorshift32 = xorin;
+			xorshift32 = xorshift32 ^ (xorshift32 << 13);
+			xorshift32 = xorshift32 ^ (xorshift32 >> 17);
+			xorshift32 = xorshift32 ^ (xorshift32 <<  5);
+		end
+	endfunction
+
+	function [63:0] lutinit(input [7:0] a, b);
+		begin
+			lutinit[63:32] = xorshift32(xorshift32(xorshift32(xorshift32({a, b} ^ `SEED))));
+			lutinit[31: 0] = xorshift32(xorshift32(xorshift32(xorshift32({b, a} ^ `SEED))));
+		end
+	endfunction
+
+	wire [(N+1)*8-1:0] nets;
+
+	assign nets[7:0] = din;
+	assign dout = nets[(N+1)*8-1:N*8];
+
+	genvar i, j;
+	generate
+		for (i = 0; i < N; i = i+1) begin:is
+			for (j = 0; j < 8; j = j+1) begin:js
+				localparam integer k = xorshift32(xorshift32(xorshift32(xorshift32((i << 20) ^ (j << 10) ^ `SEED)))) & 255;
+				(* KEEP, DONT_TOUCH *)
+				LUT6 #(
+					.INIT(lutinit(i, j))
+				) lut (
+					.I0(nets[8*i+(k+0)%8]),
+					.I1(nets[8*i+(k+1)%8]),
+					.I2(nets[8*i+(k+2)%8]),
+					.I3(nets[8*i+(k+3)%8]),
+					.I4(nets[8*i+(k+4)%8]),
+					.I5(nets[8*i+(k+5)%8]),
+					.O(nets[8*i+8+j])
+				);
+			end
+		end
+	endgenerate
+endmodule
diff --git a/minitests/timfuz/wire_unique.py b/fuzzers/007-timing/test_unique/wire_unique.py
similarity index 83%
rename from minitests/timfuz/wire_unique.py
rename to fuzzers/007-timing/test_unique/wire_unique.py
index c7b57272..2f4cc339 100644
--- a/minitests/timfuz/wire_unique.py
+++ b/fuzzers/007-timing/test_unique/wire_unique.py
@@ -1,3 +1,5 @@
+#!/usr/bin/env python3
+
 import re
 
 
@@ -29,8 +31,8 @@ def run(node_fin, verbose=0):
             return anode['wname']
             #return (anode['tile_type'], anode['wname'])
 
-        if nodei % 1000 == 0:
-            print 'Check node %d' % nodei
+        if nodei % 100000 == 0:
+            print('Check node %d, %u node types' % (nodei, len(refnodes)))
         # Existing node?
         try:
             refnode = refnodes[getk(anode)]
@@ -61,10 +63,10 @@ def run(node_fin, verbose=0):
             if k in refnode and k in anode:
 
                 def fail():
-                    print 'Mismatch on %s' % k
-                    print refnode[k], anode[k]
-                    print refnode['l']
-                    print anode['l']
+                    print('Mismatch on %s' % k)
+                    print(refnode[k], anode[k])
+                    print(refnode['l'])
+                    print(anode['l'])
                     #assert 0
 
                 if refnode[k] != anode[k]:
@@ -86,6 +88,9 @@ if __name__ == '__main__':
 
     parser.add_argument('--verbose', type=int, help='')
     parser.add_argument(
-        'node_fn_in', default='/dev/stdin', nargs='?', help='Input file')
+        'node_fn_in',
+        default='specimen_001/wire_all.txt',
+        nargs='?',
+        help='Input file')
     args = parser.parse_args()
     run(open(args.node_fn_in, 'r'), verbose=args.verbose)
diff --git a/fuzzers/007-timing/test_zero/README.md b/fuzzers/007-timing/test_zero/README.md
new file mode 100644
index 00000000..ef5ea1e4
--- /dev/null
+++ b/fuzzers/007-timing/test_zero/README.md
@@ -0,0 +1 @@
+Collect info on ZERO speed classes
diff --git a/fuzzers/007-timing/test_zero/process.py b/fuzzers/007-timing/test_zero/process.py
new file mode 100644
index 00000000..3b2ce10c
--- /dev/null
+++ b/fuzzers/007-timing/test_zero/process.py
@@ -0,0 +1,76 @@
+#!/usr/bin/env python3
+
+import sys
+import os
+import time
+import json
+
+
+def run_types(tilej, verbose=False):
+    def process(etype):
+        # dict[model] = set((tile, wire/pip))
+        zeros = {}
+        print('Processing %s' % etype)
+        # Index delay models by type, recording where they occured
+        for tilek, tilev in tilej['tiles'].items():
+            for ename, emodel in tilev[etype].items():
+                if emodel.find('ZERO') >= 0:
+                    zeros.setdefault(emodel, set()).add((tilek, ename))
+        # Print out delay model instances
+        print('%s ZERO types: %u, %s' % (etype, len(zeros), zeros.keys()))
+        print(
+            '%s ZERO instances: %u' %
+            (etype, sum([len(x) for x in zeros.values()])))
+        for model in sorted(zeros.keys()):
+            modelv = zeros[model]
+            print('Model: %s' % model)
+            for tile_name, element_name in sorted(list(modelv)):
+                print('  %s: %s' % (tile_name, element_name))
+
+    process('wires')
+    print('')
+    process('pips')
+
+
+def run_prefix(tilej, verbose=False):
+    def process(etype):
+        prefixes = set()
+        print('Processing %s' % etype)
+        # Index delay models by type, recording where they occured
+        for tilek, tilev in tilej['tiles'].items():
+            for ename, emodel in tilev[etype].items():
+                prefix = emodel.split('_')[0]
+                prefixes.add(prefix)
+        print('%s prefixes: %u' % (etype, len(prefixes)))
+        for prefix in sorted(prefixes):
+            print('  %s' % prefix)
+
+    process('wires')
+    print('')
+    process('pips')
+
+
+def run(fnin, verbose=False):
+    tilej = json.load((open(fnin, 'r')))
+    run_types(tilej)
+    print('')
+    print('')
+    run_prefix(tilej)
+
+
+def main():
+    import argparse
+
+    parser = argparse.ArgumentParser(description='Solve timing solution')
+    parser.add_argument(
+        'fnin',
+        default="../timgrid/build/timgrid-s.json",
+        nargs='?',
+        help='input timgrid JSON')
+    args = parser.parse_args()
+
+    run(args.fnin, verbose=False)
+
+
+if __name__ == '__main__':
+    main()
diff --git a/fuzzers/007-timing/tile_annotate.py b/fuzzers/007-timing/tile_annotate.py
index ffc07a21..af3d3d2a 100644
--- a/fuzzers/007-timing/tile_annotate.py
+++ b/fuzzers/007-timing/tile_annotate.py
@@ -51,7 +51,7 @@ def main():
         default='build/timgrid-vc.json',
         help='tilegrid timing delay values at corner (timgrid-vc.json)')
     parser.add_argument(
-        'fn_ins', nargs='+', help='Input flattened timing csv (flat.json)')
+        'fn_ins', nargs='+', help='Input flattened timing csv (flat.csv)')
     args = parser.parse_args()
 
     run(args.fn_ins, args.out, args.timgrid_s, verbose=False)
diff --git a/fuzzers/007-timing/timfuz.py b/fuzzers/007-timing/timfuz.py
index 581de3a0..eb9d2530 100644
--- a/fuzzers/007-timing/timfuz.py
+++ b/fuzzers/007-timing/timfuz.py
@@ -13,10 +13,76 @@ import sys
 import random
 import glob
 from fractions import Fraction
+import collections
 
 from benchmark import Benchmark
 
-NAME_ZERO = set(
+
+# Equations are filtered out until nothing is left
+class SimplifiedToZero(Exception):
+    pass
+
+
+# http://code.activestate.com/recipes/576694/
+class OrderedSet(collections.MutableSet):
+    def __init__(self, iterable=None):
+        self.end = end = []
+        end += [None, end, end]  # sentinel node for doubly linked list
+        self.map = {}  # key --> [key, prev, next]
+        if iterable is not None:
+            self |= iterable
+
+    def __len__(self):
+        return len(self.map)
+
+    def __contains__(self, key):
+        return key in self.map
+
+    def add(self, key):
+        if key not in self.map:
+            end = self.end
+            curr = end[1]
+            curr[2] = end[1] = self.map[key] = [key, curr, end]
+
+    def discard(self, key):
+        if key in self.map:
+            key, prev, next = self.map.pop(key)
+            prev[2] = next
+            next[1] = prev
+
+    def __iter__(self):
+        end = self.end
+        curr = end[2]
+        while curr is not end:
+            yield curr[0]
+            curr = curr[2]
+
+    def __reversed__(self):
+        end = self.end
+        curr = end[1]
+        while curr is not end:
+            yield curr[0]
+            curr = curr[1]
+
+    def pop(self, last=True):
+        if not self:
+            raise KeyError('set is empty')
+        key = self.end[1][0] if last else self.end[2][0]
+        self.discard(key)
+        return key
+
+    def __repr__(self):
+        if not self:
+            return '%s()' % (self.__class__.__name__, )
+        return '%s(%r)' % (self.__class__.__name__, list(self))
+
+    def __eq__(self, other):
+        if isinstance(other, OrderedSet):
+            return len(self) == len(other) and list(self) == list(other)
+        return set(self) == set(other)
+
+
+NAME_ZERO = OrderedSet(
     [
         "BSW_CLK_ZERO",
         "BSW_ZERO",
@@ -40,12 +106,8 @@ corner_s2i = OrderedDict(
     ])
 
 
-# Equations are filtered out until nothing is left
-class SimplifiedToZero(Exception):
-    pass
-
-
 def allow_zero_eqns():
+    '''If true, allow a system of equations with no equations'''
     return os.getenv('ALLOW_ZERO_EQN', 'N') == 'Y'
 
 
@@ -148,7 +210,7 @@ def check_feasible(A_ub, b_ub):
 def Ab_ub_dt2d(eqns):
     '''Convert dict using the rows as keys into a list of dicts + b_ub list (ie return A_ub, b_ub)'''
     #return [dict(rowt) for rowt in eqns]
-    rows = [(dict(rowt), b) for rowt, b in eqns.items()]
+    rows = [(OrderedDict(rowt), b) for rowt, b in eqns.items()]
     A_ubd, b_ub = zip(*rows)
     return list(A_ubd), list(b_ub)
 
@@ -411,7 +473,7 @@ def derive_eq_by_col(A_ubd, b_ub, verbose=0):
                 b_ub[row_refi] /= v
             knowns[k] = b_ub[row_refi]
     print(' done')
-    #knowns_set = set(knowns.keys())
+    #knowns_set = OrderedSet(knowns.keys())
     print('%d constrained' % len(knowns))
     '''
     Now see what we can do
@@ -648,7 +710,7 @@ def loadc_Ads_raw(fns):
 
 
 def index_names(Ads):
-    names = set()
+    names = OrderedSet()
     for row_ds in Ads:
         for k1 in row_ds.keys():
             names.add(k1)
@@ -671,7 +733,7 @@ def row_sub_vars(row, sub_json, strict=False, verbose=False):
         print(row.items())
 
     delvars = 0
-    for k in sub_json['drop_names']:
+    for k in sub_json['zero_names']:
         try:
             del row[k]
             delvars += 1
@@ -740,7 +802,7 @@ def run_sub_json(Ads, sub_json, strict=False, verbose=False):
     ncols_new = 0
 
     print('Subbing %u rows' % len(Ads))
-    prints = set()
+    prints = OrderedSet()
 
     for rowi, row in enumerate(Ads):
         if 0 and verbose:
@@ -847,3 +909,8 @@ def tilej_stats(tilej):
             print(
                 '  %s: %u / %u solved, %u / %u covered' %
                 (etype, solved, net, covered, net))
+
+
+def load_bounds(bounds_csv, corner, ico=True):
+    Ads, b = loadc_Ads_b([bounds_csv], corner, ico=ico)
+    return Ads2bounds(Ads, b)
diff --git a/fuzzers/007-timing/timfuz_solve.py b/fuzzers/007-timing/timfuz_solve.py
index 684cf05d..b3c43cfb 100644
--- a/fuzzers/007-timing/timfuz_solve.py
+++ b/fuzzers/007-timing/timfuz_solve.py
@@ -1,9 +1,10 @@
 #!/usr/bin/env python3
 
-from timfuz import simplify_rows, loadc_Ads_b, index_names, A_ds2np, run_sub_json, print_eqns, Ads2bounds, instances, SimplifiedToZero, allow_zero_eqns
+from timfuz import simplify_rows, loadc_Ads_b, index_names, A_ds2np, run_sub_json, print_eqns, Ads2bounds, instances, SimplifiedToZero, allow_zero_eqns, corner_s2i, acorner2csv
 from timfuz_massage import massage_equations
 import numpy as np
 import sys
+import math
 
 
 def check_feasible(A_ub, b_ub):
@@ -93,12 +94,50 @@ def filter_bounds(Ads, b, bounds, corner):
     return ret_Ads, ret_b
 
 
+def solve_save(outfn, xvals, names, corner, save_zero=True, verbose=False):
+    # ballpark minimum actual observed delay is around 7 (carry chain)
+    # anything less than one is probably a solver artifact
+    delta = 0.5
+    corneri = corner_s2i[corner]
+
+    roundf = {
+        'fast_max': math.ceil,
+        'fast_min': math.floor,
+        'slow_max': math.ceil,
+        'slow_min': math.floor,
+    }[corner]
+
+    print('Writing results')
+    zeros = 0
+    with open(outfn, 'w') as fout:
+        # write as one variable per line
+        # this natively forms a bound if fed into linprog solver
+        fout.write('ico,fast_max fast_min slow_max slow_min,rows...\n')
+        for xval, name in zip(xvals, names):
+            row_ico = 1
+
+            if xval < delta:
+                if verbose:
+                    print('WARNING: near 0 delay on %s: %0.6f' % (name, xval))
+                zeros += 1
+                if not save_zero:
+                    continue
+            items = [str(row_ico), acorner2csv(roundf(xval), corneri)]
+            items.append('%u %s' % (1, name))
+            fout.write(','.join(items) + '\n')
+    nonzeros = len(names) - zeros
+    print(
+        'Wrote: %u / %u constrained delays, %u zeros' %
+        (nonzeros, len(names), zeros))
+    assert nonzeros, 'Failed to estimate delay'
+
+
 def run(
         fns_in,
         corner,
         run_corner,
         sub_json=None,
-        sub_csv=None,
+        bounds_csv=None,
         dedup=True,
         massage=False,
         outfn=None,
@@ -132,8 +171,8 @@ def run(
     Special .csv containing one variable per line
     Used primarily for multiple optimization passes, such as different algorithms or additional constraints
     '''
-    if sub_csv:
-        Ads2, b2 = loadc_Ads_b([sub_csv], corner, ico=True)
+    if bounds_csv:
+        Ads2, b2 = loadc_Ads_b([bounds_csv], corner, ico=True)
         bounds = Ads2bounds(Ads2, b2)
         assert len(bounds), 'Failed to load bounds'
         rows_old = len(Ads)