openstack vm and sr-iov vs non-sriov performance

Hello

I am doing performance testing with VM using open stack and sr-iov technology.

Test scenario info:

• HOST TO VM
• 4 type of packet (64,100,220,1500)
• The time for each run is 10s.
• TCP packet
• VM is having Ubuntu OS and 768 MB RAM
• iperf is used to calculate bandwidth

Non-SRIOV Test - performed with 6 VMs running (Using neutron + openvswitch plugin )

SRIOV Test – performed with 3 VMs running. (Using neutron + SR-IOV port. NIC info: Intel Corporation Ethernet Controller 10-Gigabit X540-AT2)

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Performance bandwidth for both case 'WIthout SR-IOV' and 'SR-IOV' are almost same.

So i would like to know in which scenario SR-IOV will give better performance.

if you feel we are missing some thing in test result/ test scenario , then let me know.

Thanks

Ranjit Ranjan