diff --git a/GNUmakefile b/GNUmakefile
index 59a1e1e7..6467330d 100644
--- a/GNUmakefile
+++ b/GNUmakefile
@@ -428,6 +428,7 @@ IOARENA ?= $(shell \
   (test -x ../../@BUILD/src/ioarena && echo ../../@BUILD/src/ioarena) || \
   (test -x ../../src/ioarena && echo ../../src/ioarena) || which ioarena)
 NN	?= 25000000
+BENCH_CRUD_MODE ?= nosync
 
 ifneq ($(wildcard $(IOARENA)),)
 
@@ -441,10 +442,10 @@ re-bench: clean-bench bench
 define bench-rule
 bench-$(1)_$(2).txt: $(3) $(IOARENA) $(lastword $(MAKEFILE_LIST))
 	LD_LIBRARY_PATH="./:$$$${LD_LIBRARY_PATH}" \
-		$(IOARENA) -D $(1) -B crud -m nosync -n $(2) \
+		$(IOARENA) -D $(1) -B crud -m $(BENCH_CRUD_MODE) -n $(2) \
 		| tee $$@ | grep throughput && \
 	LD_LIBRARY_PATH="./:$$$${LD_LIBRARY_PATH}" \
-		$(IOARENA) -D $(1) -B get,iterate -m sync -r 4 -n $(2) \
+		$(IOARENA) -D $(1) -B get,iterate -m $(BENCH_CRUD_MODE) -r 4 -n $(2) \
 		| tee -a $$@ | grep throughput \
 	|| mv -f $$@ $$@.error