On 10/19/2010 09:41 AM, Pasi Kärkkäinen wrote: > On Sat, Oct 16, 2010 at 09:58:15PM +0200, Dennis Jacobfeuerborn wrote: >> On 10/16/2010 08:11 PM, Pasi Kärkkäinen wrote: >>> On Thu, Oct 14, 2010 at 02:16:42PM +0100, Bart Swedrowski wrote: >>>> Hi Karanbir, >>>> >>>> On 14 October 2010 19:59, Karanbir Singh<mail-lists at karan.org> wrote: >>>>> >>>>> On 10/14/2010 07:48 AM, Tom Bishop wrote: >>>>>> I think xen is still on top in terms of performance and features....now >>>>> >>>>> that is indeed what it 'feels' like, but I'm quite keen on putting some >>>>> numbers on that. >>>> >>>> I have done some testing some time ago on one of the EQ machines that >>>> I got from hetzner.de. Full spec of the machine was as following: >>>> >>>> * Intel® Core??? i7-920 >>>> * 8 GB DDR3 RAM >>>> * 2 x 750 GB SATA-II HDD >>>> >>>> It's nothing big but even though results are quite interesting. All >>>> tests were performed on CentOS 5.5 x86_64 with PostgreSQL 8.4 (from >>>> CentOS repos). >>>> >>> >>> Note that 64bit Xen guests should be HVM, not PV, for best performance. >>> Xen HVM guests obviously still need to have PV-on-HVM drivers installed. >>> >>> 32bit Xen guests can be PV. >> >> Hm, why would HVM be faster than PV for 64 bit guests? >> > > 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. Regards, Dennis