[CentOS-virt] performance differences between kvm/xen

Tue Oct 19 11:16:28 UTC 2010
Jerry Franz <jfranz at freerun.com>

  On 10/19/2010 03:47 AM, Dennis Jacobfeuerborn wrote:
> On 10/19/2010 09:41 AM, Pasi Kärkkäinen wrote:
>>
>> It's because of the x86_64 architecture, afaik.
>>
>> There was some good technical explananation about it,
>> but I can't remember the url now.
> In that case I'll have to call this advice extremely bogus and you probably
> should refrain from passing it on. The only way I can see this being true
> is some weird corner case.
There appear to be some interactions with the Intel VT-d processor features.

http://www.xen.org/files/xensummit_intel09/xensummit2009_IOVirtPerf.pdf

If I understand that paper correctly, HVM+VT-d outperforms PV by quite a 
lot (if you have VT-d support on your system).

-- 
Benjamin Franz