Date: Wed, 6 Jun 2007 13:51:17 +0300 From: "Abdullah Ibn Hamad Al-Marri" <almarrie@gmail.com> To: "=?UTF-8?Q?Dag-Erling_Sm=C3=B8rgrav?=" <des@des.no> Cc: freebsd-current@freebsd.org Subject: Re: Intel C2D COREs not used equally in FreeBSD 7.0-CURRENT i386 Message-ID: <499c70c0706060351x17d76eb2ge719c605cfa49e50@mail.gmail.com> In-Reply-To: <86ps49l5pc.fsf@dwp.des.no> References: <200706051316.l55DGSU0052272@lurza.secnetix.de> <86ps49l5pc.fsf@dwp.des.no>
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On 6/6/07, Dag-Erling Smørgrav <des@des.no> wrote: > Oliver Fromme <olli@lurza.secnetix.de> writes: > > It's a common mistake to assume that amd64 only makes sense > > if you have >= 4GB RAM. There are several reasons why it > > might be useful to switch from i386 to amd64: > > > > - Most programs (though not all) will run faster, because > > in amd64 mode there are twice as many general-purpose > > registers, giving compilers much better opportunities > > for optimizations and caching of values, and reducing > > slow memory accesses. > > "twice as many" is an understatement. AMD64 has 16 GPRs vs i386's 8 if > you consider BP, SI, DI and SP as GPRs (as the AMD and Intel literature > does); in practical terms the score is 12 to 4. > > > - Some applications might benefit from a larger virtual > > address space > 4 GB. (Note that this is not related > > to the amount of physical RAM!) > > For instance, Varnish maps its entire storage into memory, and will > benefit greatly from the increased address space. > > > In practice there's (almost) only one reason not to run > > FreeBSD/amd64 on amd64-capable hardware: If you depend > > on a certain piece of software which is known not to run > > correctly in 64bit mode. Fortunately those are not many. > > The only one I can think of (for a desktop) is the Flash plugin. > > DES > -- > Dag-Erling Smørgrav - des@des.no So switching to AMD64 arch would boot MySQL performance for my case 2 cores and 2 GB of ram? -- Regards, -Abdullah Ibn Hamad Al-Marri Arab Portal http://www.WeArab.Net/
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