Will AMD64 work with Intel 64 processors?

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nr5 · Post by **nr5** » Thu Jan 19, 2006 9:19 pm

Will AMD64 work with Intel 64 bit processors?

ShadowHawkBV · Post by **ShadowHawkBV** » Thu Jan 19, 2006 9:26 pm

morodoch · Post by **morodoch** » Thu Jan 19, 2006 9:32 pm

I guess it depends - itanium won't work; some of the newer pentium4 / xeon chips will, although I think they emulate some of the instructions, so they may not be as fast.

I've just tried a google for "em64t amd64 compatible" and maybe this is helpful?

http://www.google.co.uk/search?hs=q3L&h ... arch&meta=

I don't have any intel chips, though...

GJtje · Post by **GJtje** » Thu Jan 19, 2006 9:33 pm

Newest cpu's should be complete, older models were missing a few obscure instructions.

It's working nicely on my Pentium D.

wantilles · Post by **wantilles** » Thu Jan 19, 2006 9:44 pm

Yes, but with severely degraded performance due to inferior design and architecture.

nr5 · Post by **nr5** » Thu Jan 19, 2006 9:55 pm

In my case I will be getting my new server next week (PowerEdge 1850) shipped from Dell and I want to make sure I use the processors full capacity.
Its a 64-bit Intel® Xeon processor 3.0GHz with 2MB L2 cache

Will it work?

loftwyr · Post by **loftwyr** » Thu Jan 19, 2006 11:19 pm

It'll work. Just slower than the equivalent AMD64 box.

nr5 · Post by **nr5** » Thu Jan 19, 2006 11:45 pm

loftwyr wrote:It'll work. Just slower than the equivalent AMD64 box.

Will there be a big difference (noticable)? =(

nr5 · Post by **nr5** » Thu Jan 19, 2006 11:58 pm

What do you recomend I run on the server once I get it to get the best performance?

Birtz · Post by **Birtz** » Fri Jan 20, 2006 3:21 pm

nr5 wrote:
loftwyr wrote:It'll work. Just slower than the equivalent AMD64 box.
Will there be a big difference (noticable)? =(

I pretty much doubt you will notice a big difference, since all chips (being either AMD or Intel) faster than certain threshold do not bring much more or less to end user expirience. My personal opinion of this threshold is above 2 GHz speed for AMD and 3 GHz for Intel. Take this information with a grain of salt since there are people out there who do notice -fbreak-my-system-and-burn-it-down 2% level of increase in system speed

Regards

loftwyr · Post by **loftwyr** » Fri Jan 20, 2006 3:49 pm

nr5 wrote:Will there be a big difference (noticable)? =(

Probably not enough for you to notice unless you pllace them side by side. As long as you have the system set up well (hdparm settings and everything), you'd probably not notice.

IgorM · Post by **IgorM** » Sun Jun 11, 2006 3:05 pm

Good Day all,

I just wanted to join this discussion in asking if there is an alternative to amd64 for running on lets say Xeon processor?
I understand ia64 wont work?

Thanks!

-igor

loftwyr · Post by **loftwyr** » Mon Jun 12, 2006 1:10 am

x86 will work.

Beefrum · Post by **Beefrum** » Mon Jun 12, 2006 1:25 am

Yes, it'l run. And you would be missing all those nice use.. statements in the ebuilds. So now we like to watch some' quick and brite' media-violence, on your system, and I would have had to go home and go to work again

Master One · Post by **Master One** » Mon Jun 12, 2006 8:14 am

nr5 wrote:In my case I will be getting my new server next week (PowerEdge 1850) shipped from Dell and I want to make sure I use the processors full capacity. Its a 64-bit Intel® Xeon processor 3.0GHz with 2MB L2 cache. Will it work?

As far as I remember, the Xeon processors with 2 MB L2 cache do not have the EM64T implementation, so no, a 64bit installation will not work on that machine.

For those who have a Xeon EM64T, like I do, just use the amd64 install-cd, and use the following in your /etc/make.conf:

Code: Select all

CHOST="x86_64-pc-linux-gnu"
CFLAGS="-O2 -march=nocona -pipe -frename-registers"

jmmf · Post by **jmmf** » Tue Jun 20, 2006 5:31 pm

I've got a couple of Dell Precision 670n, with Intel Xeon 3.6 Ghz. (HyperThreading) processor, 4 GiB. RAM, and 2 SCSI discs arranged as RAID-0 in AIC-7901's BIOS. (Adaptec HostRAID ASR via Device Mapper)

I managed to install Gentoo x86 on those boxes, and configured them as "Scientific Workstations", mostly for number crunching and the like, but also sometimes we use them to watch media, etc. (The processors ARE EM64T (nocona), as my custom kernel was strictly compiled to boot on these, and it runs perfect.)

As a newbie to Linux 64 bits, I have several questions:

-) If I re-install Gentoo in the "AMD64 flavour", will I miss SMP / HyperThreading functionality?

-) I'm using AND DEPENDING on DMRAID v1.0.0.rc10, as my Gentoo is installed on the RAID itself. Will DMRAID compile on AMD64 platform?

-) Will "binary, static packages" compiled for normal 32 bits linux run under a 64 bit kernel? Here, we're talking about proprietary, "binary only" software, like Matlab, Maple, Nero, etc. (And also about Intel C++ & Fortran compilers & libs, bin-rpm only.)

-) Considering all the above... *IF* everythng runs O.K. under 64 bits kernel... Will it run faster or slower? (Speaking in terms of FLOPS, for example... We NEED to calculate A LOT of ugly matrixes here...

)

Well, after all... If I have my kernel compiled for "nocona-only" on x86, Will it be worth to move to AMD64 platform at all? T.I.A...

energyman76b · Post by **energyman76b** » Tue Jun 20, 2006 6:43 pm

IgorM wrote:Good Day all,

I just wanted to join this discussion in asking if there is an alternative to amd64 for running on lets say Xeon processor?
I understand ia64 wont work?

Thanks!

-igor

ia64 (aka Itanium) is completly different from x86 (32bit xeons, athlons, 486) and totally different from amd64.

It is a different architecture, with a different instruction set, that has to be compiled in special ways.

beside of that, it is really hard to get an itanium box. And this overheating, powerhungry, underperforming bastards are really, really REALLY expensive.

uxbod · Post by **uxbod** » Tue Jun 20, 2006 10:55 pm

Strip your kernel down to what is necessary in my opinion. Performance can also be achieved in other areas ... Memory speed, disks, SAN etc etc etc ...

jmmf · Post by **jmmf** » Tue Jun 20, 2006 11:42 pm

uxbod wrote:Strip your kernel down to what is necessary in my opinion. Performance can also be achieved in other areas ... Memory speed, disks, SAN etc etc etc ...

Already taken care of ALL that in my case... This is *THE* last possible optimization we can do.

Just wanted to know if that's worth with a Pentium Xeon @ 3.6 w/ HyperThreading, or just leave it running in 32-bits lands...

Spear · Post by **Spear** » Fri Jun 23, 2006 9:12 pm

jmmf wrote:
As a newbie to Linux 64 bits, I have several questions:

-) If I re-install Gentoo in the "AMD64 flavour", will I miss SMP / HyperThreading functionality?

No

-) I'm using AND DEPENDING on DMRAID v1.0.0.rc10, as my Gentoo is installed on the RAID itself. Will DMRAID compile on AMD64 platform?

Yes.

-) Will "binary, static packages" compiled for normal 32 bits linux run under a 64 bit kernel? Here, we're talking about proprietary, "binary only" software, like Matlab, Maple, Nero, etc. (And also about Intel C++ & Fortran compilers & libs, bin-rpm only.)

Sorry, don't know.

-) Considering all the above... *IF* everythng runs O.K. under 64 bits kernel... Will it run faster or slower? (Speaking in terms of FLOPS, for example... We NEED to calculate A LOT of ugly matrixes here... )

Well, after all... If I have my kernel compiled for "nocona-only" on x86, Will it be worth to move to AMD64 platform at all? T.I.A...

Assuming everything else is equal it should be faster, as the extra 8 general purpose registers only work when running in 64 bit mode on an AMD64 core.

jmmf · Post by **jmmf** » Fri Jun 23, 2006 11:04 pm

Mhh... It sounds like I'll have to do a test install on a spare Hard Disk, in order to test de "bin-only" RPMs...

Assuming everything else is equal it should be faster, as the extra 8 general purpose registers only work when running in 64 bit mode on an AMD64 core.

Yeah... I asume that... But Will it be the same under an INTEL EM64T Processor? (With the AMD64 distribution, I mean)

Thank You Very Much...

torne · Post by **torne** » Wed Jun 28, 2006 4:29 pm

Intel's EM64T and AMD64 are the same thing, from a 'what they support' point of view (well, they are now, the original EM64T had a few things missing because it was based on a prototype spec document). Anything that works on Gentoo on AMD64 will work on EM64T.

There is a slight general performance improvement in most cases on either AMD64 or EM64T from compiling 64-bit, because the compiler has 8 more visible registers (the registers are still *used* in 32-bit mode internally to the processor for register renaming during out-of-order execution, there's a lot more than 16 of them in fact - it's just that the compiler can do a better job when it gets to actually see them). There are a few pathological cases where it's faster to run 32-bit code, though, since 64-bit code tends to be slightly larger (the extra instructions are implemented with prefixes) and thus slightly less instructions fit in the icache at once.

Empire · Post by **Empire** » Wed Jun 28, 2006 9:57 pm

loftwyr wrote:It'll work. Just slower than the equivalent AMD64 box.

Uh... why?

tgh · Post by **tgh** » Sun Jul 02, 2006 12:15 am

The usual complaint about the Intel processors is memory access speed and/or memory speed due to the use of DDR2 instead of an integrated memory controller. The article over at SlashDot has the usual arguments in the Intel vs AMD fan-boy wars.

http://hardware.slashdot.org/article.pl ... 29/1714213

Don't remember if the EMT64 instruction speed was talked about it.