ESXi 5.5 system with 40 Gbps Mellanox adapters and Switchs

Hello everybody,

   We have implemented a virtualization (ESXi 5.5) system with 40 Gbps Mellanox adapters and Switchs.

  Network Adapters:

   Network Configuration:

   We are using two CentOS virtual machines and iperf to test bandwidth with the following parameters:

   VM1: iperf -s

   VM2: iperf -c VM1_IP -i 2 -t 60 -P 5

   Our best performance bandwidth it's 25 Gbps between two virtual machines.

   Host Characteristics:

   What we have tested:

   2 VMs, 4 vCpu, 4096 Gb RAM, vmxnet3, both vm on the same host connected to the same vSwitch, vSwitch without uplinks --> 25 Gbps

   2 VMs, 4 vCpu, 4096 Gb RAM, vmxnet3, both vm on the same host connected to the same vSwitch, vSwitch with uplinks --> 25 Gbps

   2 VMs, 4 vCpu, 4096 Gb RAM, vmxnet3, each vm on a different host, both host connected to the same physical Switch --> 25 Gbps

   We have installed CentOs as Operating System on the physical Host instead of ESXi and we got 37,8 Gbps bandwidth transfers, so this is not a hardware problem.

Thanks you.