diff --git a/benchmark/Makefile b/benchmark/Makefile
index 608bd59..07c7699 100644
--- a/benchmark/Makefile
+++ b/benchmark/Makefile
@@ -4,7 +4,7 @@ CXX=CL -EHsc -DNDEBUG -Fo$@ -O2
 
 ABSEIL_LIBS=absl_bad_optional_access.lib absl_bad_variant_access.lib absl_base.lib absl_demangle_internal.lib absl_hash.lib absl_int128.lib absl_internal_bad_any_cast_impl.lib absl_internal_city.lib absl_internal_civil_time.lib absl_internal_debugging_internal.lib absl_internal_graphcycles_internal.lib absl_internal_hashtablez_sampler.lib absl_internal_malloc_internal.lib absl_internal_spinlock_wait.lib absl_internal_strings_internal.lib absl_internal_throw_delegate.lib absl_internal_time_zone.lib absl_optional.lib absl_raw_hash_set.lib absl_stacktrace.lib absl_strings.lib absl_symbolize.lib absl_synchronization.lib absl_time.lib
 
-PROGS       = stl_unordered_map sparsepp phmap abseil_flat abseil_parallel_flat
+PROGS       = stl_unordered_map sparsepp phmap abseil_flat abseil_parallel_flat phmap_flat
 BUILD_PROGS = $(addprefix build/,$(PROGS))
 SIZE        = 100000000
 ABSEIL      = ../../abseil-cpp
@@ -24,6 +24,9 @@ build/sparsepp: bench.cc Makefile
 build/phmap: bench.cc Makefile $(PHMAP_SRC)/phmap.h
 	$(CXX) -DPHMAP -I.. bench.cc /MD -o $@ 
 
+build/phmap_flat: bench.cc Makefile $(PHMAP_SRC)/phmap.h
+	$(CXX) -DPHMAP_FLAT -I.. bench.cc /MD -o $@ 
+
 build/abseil_flat: bench.cc Makefile
 	$(CXX) -DABSEIL_FLAT -I$(ABSEIL) bench.cc /MD -o $@ /link /LIBPATH:$(ABSEIL)/build/lib ${ABSEIL_LIBS}
 
@@ -35,9 +38,10 @@ progs:	$(BUILD_PROGS)
 test: builddir progs
 	-rm -f output
 	#./build/stl_unordered_map $(SIZE) random >> output
-	#./build/abseil_flat  $(SIZE) random >> output
-	./build/phmap        $(SIZE) random >> output
 	#./build/sparsepp    $(SIZE) random >> output
+	#./build/abseil_flat  $(SIZE) random >> output
+	#./build/phmap_flat   $(SIZE) random >> output
+	./build/phmap        $(SIZE) random >> output
 	./build/abseil_parallel_flat $(SIZE) random >> output
 	python make_chart_data.py < output
 
diff --git a/benchmark/bench.cc b/benchmark/bench.cc
index 443e46c..540ec3f 100644
--- a/benchmark/bench.cc
+++ b/benchmark/bench.cc
@@ -13,6 +13,11 @@
     #include "absl/container/flat_hash_map.h"
     #define MAPNAME absl::flat_hash_map
     #define EXTRAARGS
+#elif defined(PHMAP_FLAT)
+    #include "parallel_hashmap/phmap.h"
+    #define MAPNAME phmap::flat_hash_map
+    #define NMSP phmap
+    #define EXTRAARGS
 #elif defined(ABSEIL_PARALLEL_FLAT) || defined(PHMAP)
     #if defined(ABSEIL_PARALLEL_FLAT)
         #include "absl/container/parallel_flat_hash_map.h"
@@ -24,7 +29,7 @@
         #define NMSP phmap
     #endif
 
-    #define MT_SUPPORT 1
+    #define MT_SUPPORT 0
     #if MT_SUPPORT == 1
         // create the parallel_flat_hash_map without internal mutexes, for when 
         // we programatically ensure that each thread uses different internal submaps
@@ -202,7 +207,7 @@ void _fill_random_inner_mt(int64_t cnt, HT &hash, RSU &rsu)
 
     auto thread_fn = [&hash, cnt, num_threads](int64_t thread_idx, RSU rsu) {
 #if MT_SUPPORT
-        typename HT::hasher hasher;                         // get hasher object from the hash table
+        typename HT::hasher hasher;                         // get hasher object from the hash table [greg] todo provide hash fn
         size_t modulo = hash.subcnt() / num_threads;        // subcnt() returns the number of submaps
 
         for (int64_t i=0; i<cnt; ++i)                       // iterate over all values
@@ -359,7 +364,7 @@ int main(int argc, char ** argv)
     srand(1); // for a fair/deterministic comparison 
     Timer timer(true);
     
-#ifdef MT_SUPPORT
+#if MT_SUPPORT
     if (!strcmp(program_slug,"absl::parallel_flat_hash_map") || 
         !strcmp(program_slug,"phmap::parallel_flat_hash_map"))
         program_slug = xstr(MAPNAME) "_mt";
diff --git a/benchmark/make_chart_data.py b/benchmark/make_chart_data.py
index a1cad32..dc15f72 100644
--- a/benchmark/make_chart_data.py
+++ b/benchmark/make_chart_data.py
@@ -44,9 +44,9 @@ proper_names = {
     'std::unordered_map':             'std::unordered_map (1 thread)',
     'spp::sparse_hash_map':           'sparsepp (1 thread, use_spp_alloc)',
     'absl::flat_hash_map':            'absl::flat_hash_map (1 thread)',
-    'phmap::flat_hash_map':            'phmap::flat_hash_map (1 thread)',
+    'phmap::flat_hash_map':            'phmap::flat_hash_map',
     'phmap::parallel_flat_hash_map':   'phmap::parallel_flat_hash_map (1 thread)',
-    'phmap::parallel_flat_hash_map_mt':   'phmap::parallel_flat_hash_map (8 thread8)',
+    'phmap::parallel_flat_hash_map_mt':   'phmap::parallel_flat_hash_map (8 thread)',
     'absl::parallel_flat_hash_map':   'absl::parallel_flat_hash_map (1 thread)',
     'absl::parallel_flat_hash_map_mt':  'absl::parallel_flat_hash_map (8 threads)',
     'phmap::parallel_flat_hash_map_4':  'phmap::parallel_flat_hash_map (N=4, 8 threads)',