The “--force-max-simd-bitwidth=64” is relatively new to DPDK (novector code path) and severely limits the performance of the burst mode of the distributor.
So modify script to add novector path expect

Signed-off-by: Lingli Chen <linglix.chen@intel.com>
---
 test_plans/distributor_test_plan.rst |  4 ++++
 tests/TestSuite_distributor.py       | 12 +++++++++---
 2 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/test_plans/distributor_test_plan.rst b/test_plans/distributor_test_plan.rst
index 7e61bef4..12fd9e9f 100644
--- a/test_plans/distributor_test_plan.rst
+++ b/test_plans/distributor_test_plan.rst
@@ -40,6 +40,10 @@ Compared CPU cycles for normal distributor and burst API
 
 Verify burst distributor API cost much less cycles then normal version
 
+The novector path severely limits the performance of the burst mode of the distributor.
+so novector: expect single mode > burst mode
+vector: expect single mode > burst mode * 2
+
 Test case: Distribute with maximum workers
 ==========================================
 Start distributor sample with 63(0xeffffffffffffffff0) workers
diff --git a/tests/TestSuite_distributor.py b/tests/TestSuite_distributor.py
index 7b41eb01..6878edbd 100644
--- a/tests/TestSuite_distributor.py
+++ b/tests/TestSuite_distributor.py
@@ -65,9 +65,15 @@ class TestDistributor(TestCase):
         )
         self.dut.send_expect("quit", "# ")
         self.verify("Test OK" in out, "Test failed")
-        self.verify(
-            cycles_single > cycles_burst * 2, "Burst performance should be much better"
-        )
+        if "force-max-simd-bitwidth=64" in eal_para:
+            self.verify(
+                cycles_single > cycles_burst, "Burst performance should be much better"
+            )
+        else:
+            self.verify(
+                cycles_single > cycles_burst * 2,
+                "Burst performance should be much better",
+            )
 
     def test_perf_distributor(self):
         """
-- 
2.17.1