Low throughput under vmware wkstn 12

  • Greetings!  Initially I was struggling getting a 1gbs throughput on my pfSense build (Atom D2550, 4gb RAM, 2x1gbps NICs on a Jetway board)..  was getting about 500gbps up/down using an internet speedtest.  All services other than minimal were turned off.  CPU was pegged all the time during the test.

    So i decided to ee how much more horsepower I will need and did a fresh install on a VMware workstation 12 VM (2 vCPU (i5-3427U), 2gb RAM, 2 virtual NICs).  NICs are on the same switch, but with are sitting on different subnets. - is being used as a WAN subnet - is being used as a LAN subnet

    Ran an iPerf test from a host on 10.0.100.x subnet to a host on 192.168.1.x and was getting about 160mbps, while CPU was at about 100% utilization.

    So I added 2 more vCPUs.  At 4 vCPUs, when I ran the same test, I was still getting identical throughput (160mbps), but CPUs were only being utilized about 45%.  mbuff seemed OK.

    I've attached output of 'top -SH'.  On a side note - I did not manually install vmware tools, assuming it's already there?  Or is everyone running it on ESXi installs tools manually?

    Any advice appreciated.


  • Anyone have any idea?

  • What vNIC were you using, the E1000 or the vmxnet3?

  • both e1000 (configured in the .vmx)

  • The e1000 NICs use more CPU if I recall.  Try with vmxnet3 instead and see if it makes any difference.

  • Switched to vmxnet3, but utilization and throughput are identical to e1000….. anything else I can try?  thanks in advance!

  • are you running multiple layer-3 over a single layer-2 ? if yes: don't

  • heper - it's [iperf client] <-> [pfsense VM] <-> [iperf server] that all sit on the same switch;

    "iperf client", "pfsense VM" and "iperf server" are each on their own hardware.

    I don't this would be considered as multiple L3 setup right?

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