diff --git a/tests/zfs-tests/tests/perf/perf.shlib b/tests/zfs-tests/tests/perf/perf.shlib
index 6f4fdc943..5a404df08 100644
--- a/tests/zfs-tests/tests/perf/perf.shlib
+++ b/tests/zfs-tests/tests/perf/perf.shlib
@@ -21,7 +21,6 @@ export PERF_RUNTIME=${PERF_RUNTIME:-'180'}
 export PERF_RANDSEED=${PERF_RANDSEED:-'1234'}
 export PERF_COMPPERCENT=${PERF_COMPPERCENT:-'66'}
 export PERF_COMPCHUNK=${PERF_COMPCHUNK:-'4096'}
-export PERF_SYNC_TYPES=${PERF_SYNC_TYPES:-'1'}
 
 # Default to JSON for fio output
 export PERF_FIO_FORMAT=${PERF_FIO_FORMAT:-'json'}
diff --git a/tests/zfs-tests/tests/perf/regression/random_reads.ksh b/tests/zfs-tests/tests/perf/regression/random_reads.ksh
index 5c8066d17..70e273166 100755
--- a/tests/zfs-tests/tests/perf/regression/random_reads.ksh
+++ b/tests/zfs-tests/tests/perf/regression/random_reads.ksh
@@ -59,6 +59,7 @@ export TOTAL_SIZE=$(($(get_prop avail $PERFPOOL) * 3 / 2))
 export PERF_NTHREADS=${PERF_NTHREADS:-'16 32'}
 export PERF_NTHREADS_PER_FS=${PERF_NTHREADS_PER_FS:-'0'}
 export PERF_IOSIZES=${PERF_IOSIZES:-'8k'}
+export PERF_SYNC_TYPES=${PERF_SYNC_TYPES:-'1'}
 
 # Layout the files to be used by the read tests. Create as many files as the
 # largest number of threads. An fio run with fewer threads will use a subset
diff --git a/tests/zfs-tests/tests/perf/regression/random_readwrite.ksh b/tests/zfs-tests/tests/perf/regression/random_readwrite.ksh
index 33d7d8c8d..4dc1e3ddb 100755
--- a/tests/zfs-tests/tests/perf/regression/random_readwrite.ksh
+++ b/tests/zfs-tests/tests/perf/regression/random_readwrite.ksh
@@ -59,6 +59,7 @@ export TOTAL_SIZE=$(($(get_prop avail $PERFPOOL) * 3 / 2))
 export PERF_NTHREADS=${PERF_NTHREADS:-'32 64'}
 export PERF_NTHREADS_PER_FS=${PERF_NTHREADS_PER_FS:-'0'}
 export PERF_IOSIZES=''		# bssplit used instead
+export PERF_SYNC_TYPES=${PERF_SYNC_TYPES:-'1'}
 
 # Layout the files to be used by the readwrite tests. Create as many files
 # as the largest number of threads. An fio run with fewer threads will use
diff --git a/tests/zfs-tests/tests/perf/regression/random_readwrite_fixed.ksh b/tests/zfs-tests/tests/perf/regression/random_readwrite_fixed.ksh
index bb4014563..cdf15c701 100755
--- a/tests/zfs-tests/tests/perf/regression/random_readwrite_fixed.ksh
+++ b/tests/zfs-tests/tests/perf/regression/random_readwrite_fixed.ksh
@@ -49,6 +49,7 @@ export TOTAL_SIZE=$(($(get_prop avail $PERFPOOL) * 3 / 2))
 export PERF_NTHREADS=${PERF_NTHREADS:-'64 128'}
 export PERF_NTHREADS_PER_FS=${PERF_NTHREADS_PER_FS:-'0'}
 export PERF_IOSIZES=${PERF_IOSIZES:-'8k'}
+export PERF_SYNC_TYPES=${PERF_SYNC_TYPES:-'0 1'}
 
 # Layout the files to be used by the readwrite tests. Create as many files
 # as the largest number of threads. An fio run with fewer threads will use
diff --git a/tests/zfs-tests/tests/perf/regression/random_writes.ksh b/tests/zfs-tests/tests/perf/regression/random_writes.ksh
index 4b826835e..30db7564c 100755
--- a/tests/zfs-tests/tests/perf/regression/random_writes.ksh
+++ b/tests/zfs-tests/tests/perf/regression/random_writes.ksh
@@ -58,6 +58,7 @@ export TOTAL_SIZE=$(($(get_prop avail $PERFPOOL) * 3 / 2))
 export PERF_NTHREADS=${PERF_NTHREADS:-'32 128'}
 export PERF_NTHREADS_PER_FS=${PERF_NTHREADS_PER_FS:-'0'}
 export PERF_IOSIZES=${PERF_IOSIZES:-'8k'}
+export PERF_SYNC_TYPES=${PERF_SYNC_TYPES:-'0 1'}
 
 # Set up the scripts and output files that will log performance data.
 lun_list=$(pool_to_lun_list $PERFPOOL)
diff --git a/tests/zfs-tests/tests/perf/regression/random_writes_zil.ksh b/tests/zfs-tests/tests/perf/regression/random_writes_zil.ksh
index 522ee4526..ff6d465bb 100755
--- a/tests/zfs-tests/tests/perf/regression/random_writes_zil.ksh
+++ b/tests/zfs-tests/tests/perf/regression/random_writes_zil.ksh
@@ -44,9 +44,10 @@ recreate_perf_pool
 export TOTAL_SIZE=$(($(get_prop avail $PERFPOOL) * 3 / 2))
 
 # Variables specific to this test for use by fio.
-export PERF_NTHREADS=${PERF_NTHREADS:-'1 4 16 64'}
+export PERF_NTHREADS=${PERF_NTHREADS:-'1 16 64'}
 export PERF_NTHREADS_PER_FS=${PERF_NTHREADS_PER_FS:-'0 1'}
 export PERF_IOSIZES=${PERF_IOSIZES:-'8k'}
+export PERF_SYNC_TYPES=${PERF_SYNC_TYPES:-'1'}
 
 # Until the performance tests over NFS can deal with multiple file systems,
 # force the use of only one file system when testing over NFS.
diff --git a/tests/zfs-tests/tests/perf/regression/sequential_reads.ksh b/tests/zfs-tests/tests/perf/regression/sequential_reads.ksh
index 2bdfff736..cc6d17245 100755
--- a/tests/zfs-tests/tests/perf/regression/sequential_reads.ksh
+++ b/tests/zfs-tests/tests/perf/regression/sequential_reads.ksh
@@ -59,6 +59,7 @@ export TOTAL_SIZE=$(($(get_prop avail $PERFPOOL) * 3 / 2))
 export PERF_NTHREADS=${PERF_NTHREADS:-'8 16'}
 export PERF_NTHREADS_PER_FS=${PERF_NTHREADS_PER_FS:-'0'}
 export PERF_IOSIZES=${PERF_IOSIZES:-'128k 1m'}
+export PERF_SYNC_TYPES=${PERF_SYNC_TYPES:-'1'}
 
 # Layout the files to be used by the read tests. Create as many files as the
 # largest number of threads. An fio run with fewer threads will use a subset
diff --git a/tests/zfs-tests/tests/perf/regression/sequential_reads_arc_cached.ksh b/tests/zfs-tests/tests/perf/regression/sequential_reads_arc_cached.ksh
index 812778636..d885d0b7f 100755
--- a/tests/zfs-tests/tests/perf/regression/sequential_reads_arc_cached.ksh
+++ b/tests/zfs-tests/tests/perf/regression/sequential_reads_arc_cached.ksh
@@ -48,7 +48,8 @@ export TOTAL_SIZE=$(($(get_max_arc_size) / 2))
 # Variables specific to this test for use by fio.
 export PERF_NTHREADS=${PERF_NTHREADS:-'64 128'}
 export PERF_NTHREADS_PER_FS=${PERF_NTHREADS_PER_FS:-'0'}
-export PERF_IOSIZES=${PERF_IOSIZES:-'128k 1m'}
+export PERF_IOSIZES=${PERF_IOSIZES:-'128k'}
+export PERF_SYNC_TYPES=${PERF_SYNC_TYPES:-'1'}
 
 # Layout the files to be used by the read tests. Create as many files as the
 # largest number of threads. An fio run with fewer threads will use a subset
diff --git a/tests/zfs-tests/tests/perf/regression/sequential_reads_arc_cached_clone.ksh b/tests/zfs-tests/tests/perf/regression/sequential_reads_arc_cached_clone.ksh
index 8ce1273c2..80081a098 100755
--- a/tests/zfs-tests/tests/perf/regression/sequential_reads_arc_cached_clone.ksh
+++ b/tests/zfs-tests/tests/perf/regression/sequential_reads_arc_cached_clone.ksh
@@ -54,7 +54,8 @@ export TOTAL_SIZE=$(($(get_max_arc_size) / 2))
 # Variables specific to this test for use by fio.
 export PERF_NTHREADS=${PERF_NTHREADS:-'64 128'}
 export PERF_NTHREADS_PER_FS=${PERF_NTHREADS_PER_FS:-'0'}
-export PERF_IOSIZES=${PERF_IOSIZES:-'128k 1m'}
+export PERF_IOSIZES=${PERF_IOSIZES:-'128k'}
+export PERF_SYNC_TYPES=${PERF_SYNC_TYPES:-'1'}
 
 # Layout the files to be used by the read tests. Create as many files as the
 # largest number of threads. An fio run with fewer threads will use a subset
diff --git a/tests/zfs-tests/tests/perf/regression/sequential_reads_dbuf_cached.ksh b/tests/zfs-tests/tests/perf/regression/sequential_reads_dbuf_cached.ksh
index adacdc297..0402b48a3 100755
--- a/tests/zfs-tests/tests/perf/regression/sequential_reads_dbuf_cached.ksh
+++ b/tests/zfs-tests/tests/perf/regression/sequential_reads_dbuf_cached.ksh
@@ -53,6 +53,7 @@ export TOTAL_SIZE=$(($(get_dbuf_cache_size) * 3 / 4))
 export PERF_NTHREADS=${PERF_NTHREADS:-'64'}
 export PERF_NTHREADS_PER_FS=${PERF_NTHREADS_PER_FS:-'0'}
 export PERF_IOSIZES=${PERF_IOSIZES:-'64k'}
+export PERF_SYNC_TYPES=${PERF_SYNC_TYPES:-'1'}
 
 # Layout the files to be used by the read tests. Create as many files as the
 # largest number of threads. An fio run with fewer threads will use a subset
diff --git a/tests/zfs-tests/tests/perf/regression/sequential_writes.ksh b/tests/zfs-tests/tests/perf/regression/sequential_writes.ksh
index d32690a05..7850bc037 100755
--- a/tests/zfs-tests/tests/perf/regression/sequential_writes.ksh
+++ b/tests/zfs-tests/tests/perf/regression/sequential_writes.ksh
@@ -57,7 +57,8 @@ export TOTAL_SIZE=$(($(get_prop avail $PERFPOOL) * 3 / 2))
 # Variables specific to this test for use by fio.
 export PERF_NTHREADS=${PERF_NTHREADS:-'16 32'}
 export PERF_NTHREADS_PER_FS=${PERF_NTHREADS_PER_FS:-'0'}
-export PERF_IOSIZES=${PERF_IOSIZES:-'8k 128k 1m'}
+export PERF_IOSIZES=${PERF_IOSIZES:-'8k 1m'}
+export PERF_SYNC_TYPES=${PERF_SYNC_TYPES:-'0 1'}
 
 # Set up the scripts and output files that will log performance data.
 lun_list=$(pool_to_lun_list $PERFPOOL)