Custom eth0 speed and esxi performance higher than expected

Hi all,

I’m new to vyos but have done ccna/ccnp stuff before so happy with how vyos is working so far. I’m using it running as a VM on an esxi host and I’m a bit confused as to some of the performance results I’m getting and just want to understand why.

I have the VYOS VM, a Win 7 VM (VLAN2) and a Server VM (VLAN3) all connected to the same vswitch in esxi. Using router on a stick and subinterfaces to route between the VLANS using VYOS, all great.

Also connected to the same vswitch is an uplink to a cisco router, which I also se tup to route between the same VLANS. Out of curiosity I wanted to see how the performance compared using LAN bench.

The cisco router is 100mbs and so I set the eth0 interface in vyso as 100 mbs full duplex (set interfaces ethernet eth0 speed 100 ) and ran the same performance test in vyos vs the physical router.
As expected, cisco average throughput was close to fast Ethernet net =88.7Mb/s.
However vyos was closer to gigabit = 670 Mb/s which is way higher than it should be, any ideas?

I don’t have a gigabit cisco router so essentially was wanting to change the variables to match for testing but no joy. Is this a vyos issue or ESXI? I changed the guest VM adapters in windows settings to 100mb but still the same result??

UPDATE: Seems its just the way esxi works, since the network traffic never leaves the same machine, the bandwidth is basically just reliant on the cpu/ram and bandwidth settings are ignored for VM 2 VM. Now thinking ill have to run VYOS as a physical machine on another host to perform the test.

when you run on e1000 and both VMs on same host, traffic never leaves host actually so you can see traffic up to gigabit,
with vmxnet3 network card even more