I find that when using VMWare Fusion 10 on macOS High Sierra and mapping a 10G capable Thunderbolt NIC, namely a Sonnet Twin 10G SPF+ Dual-Port 10 Gigabit Ethernet adaptor (Twin 10G SFP+ 10GbE Dual-Port 10 Gigabit Ethernet Thunderbolt 2 Adapter | Sonnet) through to any Virtual Machine (Windows10 / CentOS etc) it is limited to 1Gbps capabilities.
I can only get the 10G capability within the native OSX High Sierra and not in any Virtual Machine. Is this a known limitation or has anyone any advice how to resolve this issue.
Thanks in advance,
The VM gets only 1Gbps capabilities because the virtual NIC inside are either 1Gbps Intel 82455EM or 82574L (depending on the vmx configuration whether it is e1000 or e1000e).
You could try switching to vmxnet3 for the VM by editing the vmx configuration file. This requires VMware Tools to be installed as the vmxnet3 drivers come with it.
Example you could change ethernet0.virtualDev = "e1000" to
ethernet0.virtualDev = "vmxnet3"
There is a lot of commonality between ESXi/vSphere, Workstation Pro, and Fusion.
This is part of an ifconfig output on a macOS Sierra VM on Fusion 8.5 after changing the virtual adapter to vmxnet3
en0: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 1500
inet6 fe80::1ce1:eb69:a901:882f%en0 prefixlen 64 secured scopeid 0x4
inet 192.168.7.6 netmask 0xffffff00 broadcast 192.168.7.255
media: autoselect (10GbaseT <full-duplex>)
The VMXNET3 driver in macOS is actually written by Apple, so it is present in the last build of 10.11, all builds of 10.12, and was updated slightly (not clear what changed) in 10.13. Because they didn't write it, it is not supported by VMWare. While it is possible to enable it and send traffic over it in ESXi, it still only runs at 1Gbps even though it is notionally linked at 10Gbps.
TS is talking about guests that run Windows/CentOS, not macOS, so it doesn't matter as the vmxnet3 driver that is used is the one that is in the guest OS, not the host OS.
I missed that detail, apologies. In that case the only thing I can add is that in my environment, a Mac using a Thunderbolt 10Gbe NIC running as an ESXi host does provide 10Gbps performance to Windows/Linux/BSD virtual machines that have VMXNET3 support. If your client OS is supported, then hand hacking the config file should work to switch the NIC to VMXNET3. Neither Fusion nor Workstation seem to let you select VMXNET3 in the GUI even for supported client OS's.
I can confirm that the "vmxnet3" driver reports 10Gbps to windows but SMB transfers still bottleneck at 1000Gbps.
On my particular setup I have two (thunderbolt 2) 1Gbps ethernet interfaces aggregated (LAG). My tests show I can transfer files between my NAS (also setup using LAG ethernet ports) and Mac OS using SMB3 at over 1000Gbps.
On the same mac I run vmware Fusion 10 (Windows Server 2016) and the virtual machine won't transfer files faster than ~70 MBytes/s. I'm going to switch back to the supported intel driver...
Pretty annoying that the the virtual NIC doesn't match the speed of the host, wether it's bonded ethernet or a 10Gbps interface.
Did you get this resolved ?
I have a similar issue after updating to 10GB ethernet
Native performance shows 10 gigabit speeds, VM not so much
I found the easiest way to test is to use iperf3, which you can run in docker for instance on the NAS, or on an actual machine.
I did try the vmxnet3 driver, its better but still not full speed.
I also changed MTU to 9000 on both the physical the virtual device