On Tue, Oct 19, 2010 at 12:47:03PM +0200, Dennis Jacobfeuerborn wrote: > 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. > It's not bogus, you can go ask on xen-devel :) -- Pasi