Hi friends,
I have a strange Hyper-V issue. (It came up during attempts at diagnosing lousy DNS forwarder performance - now I want to understand and preferrably fix the below, first.)
My home lab has 40 Mbps fiber to the Internet, and 2 server PCs: Windows Hyper-V Server 2012 R2 and Windows Server 2012 R2 Standard (also with Hyper-V role). For this discussion, they are up-to-date and behave identically.
I've tried Speedtest and testmy.net, results are the same.
When tested from either a Hyper-V host or a VM, each connection maxes at only ~3.5 Mbps. I can start many connections in parallel (I've had max 5 running) - each maxes at ~3.5 Mbpps! It doesn't matter if the connections are from several processes
on the same VM, or from a mix of hosts and VMs.
So it seems neither host nor VM is throttled to 1/10 of the fiber capacity - it's as if each connection is throttledindividually!
Transfers inside the LAN (e.g. from my NAS to a server or VM) does not have this cap applied - then I get ~800 Mbps.
Any other client (Android phone, Windows 10) on my LAN or WLAN is able to max out the fiber at ~40 Mbps.
Obviously, I'd blame my cheap Netgear RP614v4 router if it wasn't for that last fact.
I've made sure VMQ and offloading are disabled (my NICs are basic Intel), no teaming, no QoS policies.
I can't make sense of it - does this ring anybody's bells?
Best regards,
Robert