re: Hyper-V: How to make sure you are getting the best performance when doing performance comparisons

William Fields — Fri, 10 Oct 2008 15:51:35 GMT

Hello,

I'd like to see some file transfer performance numbers on your end. Also, I'd like to know (or clarify) a couple things.

My understanding (http://blogs.technet.com/jhoward/archive/2008/06/16/how-does-basic-networking-work-in-hyper-v.aspx) is that when transfering data from parent to child through the virtual network switch (Synthetic NIC, and VMBus active), there should be no actual traffic between the physical NIC's (in a dual-NIC system). See: http://blogs.technet.com/blogfiles/jhoward/WindowsLiveWriter/HowdoesbasicnetworkingworkinHyperV_B633/14_2.jpg

When I monitor the physical NIC's via performance monitor, they show that they're passing the traffic out of my physical box, to the physical switch (GB full duplex), then back into the box. And BTW - the data is also passing through the virtual switch. Note, this is passing data to/from a WinXP guest. This graphic shows what I'm talking about http://blogs.technet.com/blogfiles/jhoward/WindowsLiveWriter/HowdoesbasicnetworkingworkinHyperV_B633/13_2.jpg

#2 - Even though my physical system has dual-GB NIC's, and a full duplex GB switch, the data transfer rate from parent to child partition is equivalent to a poor porforming 100mb network (<5,000,000 bytes/sec). What's up with that? I should be seeing 20+ million bytes/sec on a GB system.

I've posted this to this blog entry as well as John Howards.

Any feedback would be great. Network file transfer performance numbers would be wonderful! I'm very excited about Hyper-V, but I'm not sold on performance yet.

Thanks.

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[Tony's Reply]

Performance data is coming...

http://blogs.msdn.com/tvoellm/archive/2008/09/24/what-hyper-v-storage-is-best-for-you-show-me-the-numbers.aspx

As for the networking performance you are seeing from guest to host when using a public switch (is a switch attached to a physical NIC) is you least performant option because you are also depending on your switch to send back the packets. If you want guest to host performance you should use a private switch. There are also factors that you might check out firewall, filtering, ... You also want to make sure you have LSO and TCP offload enabled on the virtual switch.

You should check out SQL and BizTalk papers...

http://blogs.msdn.com/tvoellm/archive/2008/10/07/sql-server-2008-on-windows-server-2008-hyper-v-performance-guidance.aspx

and

http://blogs.msdn.com/tvoellm/archive/2008/07/22/biztalk-team-releases-best-practice-doc-for-running-on-ws08-hyper-v.aspx

Hyper-V Performance FAQ

ALL TOPICS PERFORMANCE — Fri, 06 Jun 2008 06:27:59 GMT

Hyper-V Performance FAQ Anthony F Voellm (aka Tony) 6/5/2008 http://blogs.msdn.com/tvoellm Q: What is

re: Hyper-V: How to make sure you are getting the best performance when doing performance comparisons

Pete — Mon, 21 Apr 2008 16:35:41 GMT

Graphics for Pitfalls 1 & 2 are switched

[[Tony- Thanks Pete - Fixed]]