Hardware Selection for AMD64 + Linux?

MrClever asks: "After a disaster involving my cat, a pot of coffee and my workstation, I am now in the market for a new machine. I thought I'd jump on the AMD64 wagon and keep running Linux. After some initial investigation, it became clear that ATi, Promise and other manufacturers don't have 64bit drivers for Linux, which rules out most motherboards with onboard P/SATA RAID, thus limiting my available choices. I know you can run 32bit on AMD64, but if I wanted that I'd get an AthlonXP. So, what AMD64 hardware is the best supported in 64bit mode under Linux? Seems NVidia have 64bit drivers, does anyone else?"

Comments

don't buy an Athlon 64 until new socket comes out!

[Tumbleweed]

Wait for Socket 939 boards & CPUs - the current Socket 754 has a very limited lifespan. Socket 939 processors are due VERY soon now (just saw the first leaked report on one yesterday). FYI.

Of course, this doesn't apply if you're thinking about the Opteron, with its Socket 940.

Hardware RAID on the motherboard

[jmauro]

Most of the RAID on the motherboards are really software RAID that runs in a Windows driver or Linux driver. Since each slot usually shows up as a normal PATA or SATA device, one could then just use Software RAID under linux and get the same effect as the "on board" RAID under 64-bit x86.

Re:Hardware RAID on the motherboard

[photon317]

The real difference is just that the exact layout of the raid is a pre-set standard by the BIOS vendor, and thus if you run Promise or whoever's softraid drivers in both OSes, you can have multi-platform softraid for a dual-boot setup. Linux boots just fine from a software raid device on it's own without this stuff, I assume windows can do the same.

Re:Hardware RAID on the motherboard

[aminorex]

But that "drive" can be a ramdrive, or a tiny partition which is mirrored and never mounted after
boot. I don't see the disadvantage, frankly.

Even the CPU cost of soft RAID is vanishingly small
these days, when caches are 2-8MB and CPUs are
approaching 5000 bogomips.

I see the difference as being MORE PORTS. Lets
me cram more drives into the box.

Promise works fine

[OrenWolf]

The Promise controller on the Tyan Opteron motherboards works perfectly in both Red Hat Enterprise Linux (with Update 2), and Fedora Core 1/2 for AMD64.. That same chipset (PDC20378) is available on Athlon64/AthlonFX motherboards as well.

Consider 3ware...

[isaac]

3ware cards work a treat in amd64 systems with one caveat - using the PATA Escalade 7500-series cards on the Tyan Thunder K8W (opteron) MB is asking for trouble. The SATA cards work fine.

Promise is junk anyhow; it's not a hardware raid controller, just a dumb ATA controller card with software RAID drivers.

Just do your own software raid in Linux or buy a real (e.g 3ware) controller.

-Isaac

Re:Consider 3ware...

[Anonymous Coward]

make sure your 7500s are on PCI-X A *NOT* B.
everything should be fine except the 7500s are a PoS. Hardware RAID like Intels boards are much better. or just use linuxes software raid which is much more stable anyway.

Search the support databases of linux distributors

[Rauchbier]

Maybe the support database of a linux company like SuSE may be helpful.

Re:Software selection

[Paladin128]

• I'm guessing that you are planning on running very large memory applications (> 2 Gig per process), otherwise 64bit support is useless.

Not at all true! AMD64 has twice the number of general-purpose registers available in 64-bit mode. Some apps also just run faster in 64-bit, like POVray.

SATA with promise chipset works

[MerlynEmrys67]

I am running Fedora Core 2 on a dual opteron Tyan motherboard. I have a 80Gig SATA drive that works fine right out of the box (FC 1 didn't see it though, in fact FC 2Test 3 didn't either)

Dual opteron just rocks

VIA BIOS problems

[S.I.O.]

I'm using a VIA-based Gigabyte m/b and basically everything works fine (SATA, sound), but the famous AMD HALT bug is still not fixed in the latest BIOS, so the kernel is running in polling mode. It means that the CPU cannot switch to sleep mode when there's nothing to do. *Very* irritating. BIOS coders are eventually more evil than trade mark/IP lawyers.

Slackware doesn't come in 64bit :(

[arfonrg]

I just got a Presario R3000 (R3140US to be exact) and it's not bad.

Linux (slackware) runs just fine in 32bit mode. Even faster than the WinXP that came with it.

It's got the Nividia Video/sound chipsets, Broadcom wireless, RTL8139 ethernet, and modem built in. All I have working (the Broadcom needed the Linuxant driver but it's working like a charm).

I haven't tried the modem yet, but I may in the future.

To answer your question, Linux works fine in 32 bit mode on AMD64s. I'll let you know how 64bit Linux works when Slackware comes out with a AMD64 version.

Sorry to cut this short but, work calls

Re:Software selection

[Too Much Noise]

the recompile has to do with performance jumps of amd64 in 32bit mode vs. 64bit mode with the same compiler (gcc). Now, if you compiled the 32bit code with icc and had fp math that icc likes, you won't see much of an increase for gcc-compiled 64bit code vs. icc-compiled 32bit one. But you might still see faster code, depending on the particular app. That is due to a bunch of factors:

• scalar math w/ 16 SSE2 registers vs. vector math with only 8: you can balance out the timings between loads and math ops; in particular, unaligned loads hurt less (besides, AMD's SSE2 unit behaves about the same in scalar and vector mode anyway from typical benchmarks - if you really want timings for that I can check it)
  
• 64-bit registers mean easier data moves between GPRs and SSE2
  
• not least, cache and integrated memory controller issues.
  
• drawback: clock speed is actually important for fp math crunching, so athlon64 is handicapped here.
  

besides, those benchmarks don't show such a 'clear' difference. An amd64 3200+ slower by 5% than a p4@3GHz in 32bit mode w/ WinXP. Not exactly relevant for 64bit.

Re:Software selection

[Too Much Noise]

not just instability. Try filling all the slots in a desktop box (read: non-ECC memory) and you'll see the RAM speed throttle down. You get a trade-off, speed for size. Server-type memory doesn't have that problem with all slots full (different addressing scheme for ECC, if I remember correctly).

Precisely ...

[vlad_petric]

For modern processors accessing the register file is considerably faster than accessing the memory (even if the memory access doesn't miss in the L1 cache). With 8 GPRs, the compiler can barely alocate 3 for variables (the rest are needed by the compiler for other stuff). That number increases to 10->11 when going to 16 GPRs. This means that for small leaf functions you don't need to go to memory at all ...

The performance increases of 10-20% is precisely what people got by recompiling with gcc for AMD64. This is, indeed, the reason 64-bit architectures perform better than standard x86/32 bits (Itanium has 128 GPRs for instance ...)

My amd64 linux system

[riprjak]

is simple
MSI k8t neo FSIR2 motherboard (some issues with slow bios upgrades)
MSI Geforce FX5950ultra 256MB
Soundblaster Audigy
2 x 120GB ATA4 HDD
1 x 36GB SATA 10k drive
1 x dvd+/-rw CDrw combo
amd64 3200+
1 GB (2 x 512MB) kingston ddr333

This system runs gentoo 2004.1 64bit linux fine. SATA and PATA work fine, but there is not now nor, hopefully, will there ever be support for Software RAID as you find on motherboards (it is pointless feature creep IMHO).

Whilst I would say that ASUS appear to be on the ball with bios updates compared to MSI, my system runs fine (even manages wine using 32bit compatibility libraries and runs windows progs...).

I wholeheartedly recommend 64bit linux and would say that EVERYTHING works except high end ATI radeons (ATI couldn'f find their arsehole with two hands and a roadmap in 64bit terms) and many 802.11g cards (mostly due to the atheros binary driver crap, but support is slowly improving). Couple this with *no* support for software RAID (which is no real use anyway) and you nicely encapsulate most of the problems with 64bit linux. Sure, grub and lilo dont play well at 64 bit, so you will need a liveCD or a chrooted 32bit environment to build them (and some other apps); but 32bit apps execute fine as long as you have a set of 32bit libraries for them to play with.

Go for it, join us, we tools who double as early adopters... then you too can whine at manufacturers for their tardiness in supporting "production ready" 64bit OS'... lol

hope this helps...

err!
jak.

64-bit performance revisited

[kompiluj]

This is a comparison done on sparc platform between 64 and 32 bit modes highliting some performance issues. There are two most important things:

• Amount of performance you'll gain/lose when switching to 64 bit mode depends on the application you intend to run (for instance big gains on SSH/SSL )
• sizes of executables (programs, libs) are significantly larger in 64 bit mode

Of course in the case of AMD64 you will also gain something because of ability to use more registers, which is not the case with sparc.
And one more thing - do take a look at the Solaris 64-bit Developer's Guide. They have done the migration 32->64 long time ago. Learn from them.

platform DOES matter

[David Jao]

Most of this post is just pure misinformation. Some of it has already been corrected in the replies. I will focus on the bits that have not yet been corrected.

Just today I had a user mail me with an error with rcp because it could not transfer a file that was 2.1Gigs.

For example, cat over_2Gig_file > /dev/null will fail

I could see this as being true "6 or 7 years" ago, but any remotely modern linux distribution will NOT have a problem with this, even on 32-bit platforms. Here is a screenshot debunking your claims for both rcp and cat.

Perhaps your problem is that you're not compiling your applications using the large file support API, which all modern distributions do for you whenever possible.

You will find these limitations from time to time, and rarely does the platform matter.

You take a look at this screenshot and try to tell me that platform doesn't matter.

Also, Linux has other limitations like it cannot access a block device over 1 or 2 Tb (depending on the kernel version).

Ironically, the one limitation that you do state correctly is also one of the limitations that only applies to 32-bit systems. It sounds like you need a 64-bit system after all, preferably a modern distribution like Fedora 2 or SuSE 9.1 that doesn't have any of the weird userspace problems that you bring up.

Don't own one

[anti-NAT]

however, I think the ATI 9200 series meets your requirements.

The http://dri.sf.net project is the place to get the scoop on fully open source supported 3D cards.