64-bit AMD purchase advice
 

I'm planning to assemble a computer to run large (data size) programs under a 64-bit kernel.

I'd like some advice, especially warnings about any pitfalls in my tentative plan.

I'm pretty sure I want the Athlon X2 6400+ Windsor 125W Dual Core.

I may decide either 4Gb or 8Gb ram.

I'm considering the ASUS M2A-VM HDMI motherboard. (AMD 690G, ATI SB600, ATI Radeon Xpress 1250 on board).

I need high resolution graphics (many pixels on screen) but NOT high performance graphics (fast screen updates, gaming, etc.) If I choose a different motherboard without integrated graphics, I'm considering a very low cost card such as Sapphire 100184L (Radeon x1300 PCIx16 with 128Mb ram). I never understood what display cards need with all that memory. The highest resolution graphics at 4 bytes per pixel is still just a fraction of the 128Mb. Or am I missing some reason a non gaming high resolution display needs more display card memory?

I want IEEE 1394 (which is on-board the M2A-VM HDMI). I want to be able to load movies from my camcorder through its firewire connection (but that won't be the primary use of the system). I haven't even started yet to investigate what software is required to do that in Linux. Warn me if that is hard.

I am willing to pay a moderate amount extra for faster ram. But I don't understand what is compatible with what. Within DDR2-800, the memory with timing 4-4-4-12 costs a moderate amount more than 5-5-5-15. The M2A-VM motherboard I recently bought doesn't report nor give you access to adjust that timing. It wasn't clear that it understands anything other than 5-5-5-15 (which is what I bought for the lower performance system I just built). (I haven't tried any BIOS upgrades yet). I don't want to pay extra for performance I won't get. Also the voltages are higher for the 4-4-4-12. I don't know what ram voltages the motherboard supports, so the faster ram might not work at all.

Even more so for memory faster than DDR2-800. The motherboard manuals really don't make clear what they support (Asus forum seems to say that only works 2x2G not 4x2G, so I couldn't get 8GB).

If I choose integrated graphics, does the load on main memory for graphics refresh slow down memory noticeably for the CPU? In which case, it doesn't make sense to save $20 by avoiding that cheap display card then spend much more than $20 incremental for faster ram.

I want a low cost DVD burner. I have no clue about software compatibility for Linux. I don't care about speed. I won't be burning many DVDs. I just want to be able to.

I think I can decide on the SATA hard drive and the power supply, case, keyboard, mouse, etc. without any advice.

I'd prefer to use a Debian distribution of Linux. I'm still a Linux newbie and Debian is the one I'm using on another computer and the one I'm starting to understand. But if there are any Debian specific pitfalls in the above plan, or any other strong reason to choose a different distribution, please warn me.

The motherboard I mentioned includes Realtek RTL8111b network port on board. Windows XP does not support that on first boot. You need to install the driver from the included CD-ROM after installing XP and before using the network. Does Debian need something similar? How do I insert that into the process? The only way I've installed Debian is booting a standard minimal image from a CD-ROM and letting it find what it needs over the network.

Well, for Radeon cards you mentioned you will need the proprietary fglrx drivers from catalyst. They are available from the ATI/AMD website, but still not very good, you might say. Though, they work.
As to the amount of memory for videocards, you can think of double and even tripple buffering, different other buffers, all sorts of texturing and vertex work a GPU has to do... That would explain the amount of memory it needs...

Yes, but for most folks, it makes more sense to have a faster GPU chip than a load of RAM on the card.

As for the Realtek, I have one of those. It has been supported by Linux for about a year now and CentOS is the only big distribution I can think of that still requires one to compile the driver oneself. I'm not sure about Etch, though, it depends on the kernel. Anything 2.6.18 or up should have it.

Also I would recommend a SATA dvd burner, they have never let me down while I do remember a few occasions where a kernel update caused the IDE drives to misbehave. They aren't any more expensive and you can finally get rid of those ugly IDE cables.

RAM. Yes, it's true, ASUS isn't very clear about what works and what doesn't. I upgraded to 4 GB some months ago but only after doing plenty of research to find whether it worked for others with the same motherboard. Anyway, that motherboard you mention has a 400Mhz max FSB so it should be pc6400 RAM (i.e. 800Mhz).

Oh yes, and another thing, if you will be running Windows on that board, you'll almost certainly have to flash your BIOS to get it to work properly.

Just stay away from ATI in Linux. It is far, far, far, easier to use Nvidia in Linux.


Just look and see what speed you motherboard manual calls for. When you buy memory think ahead. If there is any chance that you may need to upgrade, make sure you leave open slots. If you fill all your slots to get to 4GB then decide you need 8GB, you will have to get rid of all the memory you bought the first time (I see this almost every week).

I'm not gaming, so I don't care how fast the GPU is.

If I can ever interrupt my son on his new M2A-VM motherboard running Windows XP. I'll try to boot my Knoppix (5.1.1) DVD and see how it handles that hardware, especially network. I'm pessimistic because (when I recently downloaded my copy) Knoppix hadn't been updated since 2007-01-04.

I'll look into it. But I don't recall any SATA models in the list of lowest cost DVD burners at NewEgg.

Another thing I don't understand is where the FSB fits in on an AM2 socket motherboard. All the diagrams I've seen show the CPU talking directly to ram and the FSB on the other side of the CPU, talking to everything else. So the FSB speed (which claims to be 2000Mhz) may not matter much. Except in their forum, they do seem to say the memory is limited to 400Mhz (DDR2-800). But in the forum they say you can go up to 533Mhz if you only use two memory slots not all four.

Off topic for this thread, but I want to know about that as well.

My son is using M2A-VM motherboard, 2.5 Ghz Athlon X2 Brisbane, 2Gb ram (5-5-5-15), running Windows XP. No obvious problems. I haven't tried any BIOS upgrade. What did you expect to fail without flashing the BIOS? What BIOS would I flash to? Latest does not seem to mean greatest in BIOS's for that board.

I'm considering an M2A-VM-HDMI similar motherboard for myself for Linux.

If I were less of a newbie at Linux I would do some testing with a bootable DVD: Create some .iso image while running on my really lame (hardware) Debian Linux box. Copy .iso over home network to my son's XP system. Burn DVD, Boot DVD. Test something. If you can point me at directions a newbie could follow for creating that .iso file, I would love to test before purchase the Linux 64-bit kernel support for all the parts that might be in common between my son's XP box and my planned Linux box.

OK, here are the specs that are relevant to RAM:

There are plenty of other livecds that are more recent that that. Mepis, Ubuntu, openSuse, Fedora, Mandriva One - and those are just some of the more important. The first two are Debian based so they should give you the best idea if you are going to use Debian.


Well, I understand that the HDMI on the board has been a massive problem for quite a few Windows users before they upgraded the BIOS. BSODs and more of that sort of fun.

Here is where you lose me. What do you mean exactly by "create an iso image"? Would you like to build your own or do you mean using a pre-made liveDVD?

Thanks for clearing that up. I guess I confused things by talking about two similar motherboards. Windows XP 32-bit on M2A-VM (which has no HDMI and no IEEE 1394). Linux 64-bit on M2A-VM-HDMI. I don't expect to use HDMI, but the HDMI version of the board seems to be the easiest way to get IEEE-1394.

Maybe I should be more optimistic about what I can find in a liveCD or liveDVD .iso file already packaged by someone who knows what they're doing. I'll try searching for it tomorrow.

I was assuming I wouldn't find what I needed that way and would need to build something.

Minimally I would want a liveCD or liveDVD with a 64-bit kernel, with KDE, with a display driver that understands the built-in Radeon 1250 well enough to get to 1280x1024 desktop, with a driver that understands that network port, etc., with other basic things I would assume are on any liveCD.

That should let me test enough to estimate whether I'll be OK with the similar motherboard.

I would say, the 64 bit live/installer CDs of Mepis or Ubuntu, those come closest to Debian Lenny.

I'll try that tomorrow to see if there are any surprises with 64-bit kernel.

But I'm typing this on that M2A-VM system now, running (32-bit, one-year-old version) Knoppix from DVD (I finally got my son to go to bed). I thought Knoppix had failed when the screen flashed on and off for a long time when it was starting X. On other computers that has meant the xorg.conf file isn't good enough and needed tweaking before X could start. But on this system it got past that and started X. So I guess good enough support for this Radeon 1250 and this network port has been in Linux for over a year.

BTW, here are some of the more significant details as detected by Knoppix:
(--) PCI:*(1:5:0) ATI Technologies Inc unknown chipset (0x791e) rev 0, Mem @ 0xf0000000/27, 0xfdbf0000/16, 0xfda00000/20, I/O @ 0xcc00/8
(II) VESA(0): Total Memory: 256 64KB banks (16384kB)

02:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168B PCI Express Gigabit Ethernet controller (rev 01)
Subsystem: ASUSTeK Computer Inc. Unknown device 81aa

00:14.2 Audio device: ATI Technologies Inc SB600 Azalia
Subsystem: ASUSTeK Computer Inc. Unknown device 8249

Edit: Now I tested Mepis-CD_7.0-rel_64 as well. Everything looks basically OK. The above hardware detect info is all duplicated by Mepis, even the "unknown chipset" part, despite Mepis being much newer. But none of those unknowns seem to stop the device from working.

There are a lot more minor glitches than I expected (seg faults list in dmesg, things break if you try to do anything before KDE is all the way up, etc) but nothing that would be a show stopper. To the extent that Mepis has more of those than Knoppix, I think it is more likely an issue of 64 bit vs. 32 bit than something wrong with the Mepis distribution.

So my major worries about compatibility with this motherboard are all gone.

But I'd still like to get a little more advice and/or warnings on the basic plan and questions from my first post of this thread.

I have more questions about this topic (in addition to those items from my first post that still haven't gotten responses).

I think I will want to be able to run both 64-bit and 32-bit (PAE?) kernels. How should I partition for that? Or are the issues already covered by directory structures and paths within one partition?

I expect I will want some 64-bit builds of standard programs when using the 64-bit kernel. I assume those won't run with a 32-bit kernel. I assume (correct me if I'm wrong) that most programs aren't available in 64-bit unless I compile them myself. So I'd want the same (32-bit) version for use with both kernels. I don't mind the waste of disk space to duplicate all that. But if there is a cleaner way, please suggest it.

I expect I'll want /home separate from root and have a single /home partition used from either kernel. But what else should be in common between the two roots?

What do you think of using aufs instead? Assuming I mainly use 64-bit, I could have a normal directory structure with the mix of 64-bit and 32 bit content one would normally use with a 64-bit kernel, then have a second structure placed in front of it by aufs with 32-bit versions of all those things that are 64-bit in the normal version.

But I don't know how the package manager keeps track of what is installed. Would it get badly confused from having aufs turned on and off as implied above?

At least for Fedora, all the packages that are available in 32bit are available in 64bit via yum(package manager). You can run 32bit apps on a 64bit OS, if you have to(but not the other way around).

Just to be clear there are a number of apps that are reported not to like PAE.

Unless you have a lot of linux experience already I would just stick with the Ext3 file system. Later, if you want you can do a full backup and then switch.

It's a bit unclear for me why you'd want to run two kernels? User rarely come into a direct contact with the kernel...
Ithink you just need to install a multilib distribution. Actually, almost all of disros are multilib now, only a few are pure 64-bit.
If you install a multilib distribution, the distro itself will take care of that.
And no, most programs _are_ available in 64-bit, only a very small number of packages don't have a 64-bit version (like Adobe flash). I'm using a pure 64-bit distro, I don't experience any shortage of software... :)
Like I said, don't make two roots, install a multi-lib distro.
A multi-lib distro will take care of that.

I suggest using ECC when ever possible. The benefits of using ECC memory is a more reliable and stable computer. It becomes required if you are going very high capacity. Yes, AMD processors support ECC memory even though the motherboard manufacture does not state it.

Do not worry too much on timing. IMHO, keep it high for increase stability and reliability. When setting it low, you will sacrifice stability and reliability.

Selecting higher model graphic cards such as a GeForce8 8800 Ultra, you can process more data quickly. These new graphic cards are now able to process other kinds of data besides graphics. One problem you have to create the software to process the data from the graphic card. Just select models with a lot of video memory to do this. At least 768 MB or more. The amount of gigaflops is between 10 for lower end models to a few hundred gigaflops for the very high end models. What this means near super computer speeds.

Integrated graphics uses main memory for video memory. Also it takes up memory bandwidth.

I would go for GIGABYTE GA-M68SM-S2. It comes with nVidia graphics which is a lot easier to work with in Linux. You do not need to find a motherboard with HDMI connector because you just need an DVI to HDMI adapter. IMHO, ASUS are becoming Windows dependent and are not that good any more. The Gigabyte board is better and cheaper. It can handle 16 GB of memory while the ASUS board can only handle 8 GB.

For the processor, make sure it does not have an odd multiplier. The following link explains about it.
http://www.anandtech.com/cpuchipsets...px?i=2762&p=10

Not all programs benefit when they are compiled with 64-bit instruction architecture. Mostly multimedia programs and some games will work faster, but daily programs will not. Some programs may perform worst.

Be careful selecting the power supply. All power supplies are not created equal. The saying you get what you paid for does prove in the buying decision of power supplies. You pay more, you get a quality power supply. You pay less, you get crap. Spend some time at xbitlabs.com and other review sites that have tested power supplies thoroughly. I suggest either Seasonic or Enermax.

I suggest Western Digital 'Raptor' series hard drive. The reason is because they are fast. They have an accessing time of 5 ms and they perform well in file serving which means great for general task or daily tasks of loading programs.

I prefer IDE/ATAPI optical drives because they are more reliable. Also a lot easier to deal with than SATA optical drives. In the past SATA optical drives are not reliable.

I suggest Gentoo Linux instead of Debian. Sure Debian is OK, but they use pre-compiled programs. People said Gentoo goes for speed. This is wrong. Gentoo goes for reliability and stability.

Thanks. I guess you convinced me to be less interested in trying a 32-bit PAE version than I thought I was. And if I try it later, to be less interested in trying to share installed packages with the 64-bit install.

I don't know what "multi-lib distribution" even means. Maybe I'll do some searches. But since I installed the 32-bit Mepis on my junk hardware Linux system, and tried 64-bit Mepis liveCD on my son's new Windows XP computer, I'm convinced that is the distribution to use when I assemble the next computer. I like to do as much sys admin in GUI mode as possible and go to command line only when necessary. Mepis seems to support that better than other distributions. Also its documentation is much better, even for the command line sys admin tasks.

Thanks, but: I've seen statements like that a lot, but never any convincing explanation. I think ordinary computer hardware is very reliable and stable already. Most malfunctions are software. I'm assembling a system for software experimentation, not for transaction processing. I don't believe the supposed connection between the amount of RAM and the need for ECC. The connection should be to system use (especially transaction processing).

I'm sure setting it lower than its official specs sacrifices reliability. But what about paying extra for memory with faster official specs (as I asked in the first post)? Are you saying it is less reliable to run that memory at its official specs than to run cheaper slower memory at its official specs? Do you have evidence/links to support that? I'd definitely like to know before making that decision.

As for worrying about timing: In my regular job I develop software for some large data problems that have heavy miss rates on a 1Mb L2 cache. If the ram timing were 25% faster, the whole run would be 23% faster. I may want to do some things at home with similar timing characteristics and/or if I get faster ram at home than I have at work, bring some of the tests I would run at work home.

I wish I knew how much bandwidth.

I wondered about that as well. Both have four ram slots. Are 4G sticks of DDR2-800 available anywhere at close to a reasonable price? Is the 8G limit in the ASUS a hardware limit, or does it just mean they haven't yet updated their BIOS to support 4G memory sticks (but probably will when 4G memory sticks are reasonably available)?

I figured that out after buying the 2.5GHz CPU for my son. With an AM2 socket, if the CPU internal clock isn't divisible by .4 Ghz, you can't get safe full speed from DDR2-800 memory. That makes a big difference on my system (fortunately not on my son's system) so I will get a 3.2GHz CPU.

I was wondering about that as well. I was surprised to read in various Linux forms that 64-bit programs are normally faster. It's one of the things I want to experiment with and learn about. The product my employer makes is built both 32-bit and 64-bit. We had a big struggle getting the 64-bit performance even close to as fast as 32-bit. Some of the problems simply can't be run in 32 bit. But those that can run in 32 bit, all run faster in 32 bit. I think we did a good job getting the 64 bit build to use 32 bit data types for all data where that is appropriate (large arrays of 64 bit data have more cache misses than 32 bit data and performance is often dominated by cache misses). That 32-bit vs. 64-bit comparison is unfair because we don't use the same compiler. We use an Intel compiler that gives better performance than either GCC or Microsoft. But for 32-bit we use a very old version of that compiler because each newer version gave worse performance than the last. For 64-bit we use a fairly new version because the fastest version had no 64-bit support at all, and intermediate versions had buggy 64-bit support. I probably want to experiment at home to understand whether 64-bit vs. 32-bit bit issues other than compiler quality are still contributing to that performance problem.

I'll select some WD drive because I trust them. But I'll select mainly on price/capacity, not speed. Most of my hard drive performance issues at work are caused by brain dead limits in Windows XP32's caching rules when hit with thousands of tiny files and directories (with lots of ram available, the number of small files cached is limited to far fewer than available cache memory would suggest).

I expect/hope that Linux (especially 64 bit) won't have any similarly stupid limits. So I expect in a large ram system to barely touch the disk in an edit/compile/test/repeat cycle with small or moderate size test cases. I may want some advice on how to tune (maximize) write-behind behavior for data (such as object files) where the cost to recreate them in case of a crash is low.

Linux has FAR better memory management than Windows. I've had an up time in upwards of 3 days (currently) and my swap has not been touched ONCE. I'm using a 32-bit SMP kernel. I only have 1GB of RAM running Fedora 8. If you're using 4GB of RAM, I imagine you'll have the same experience as me... a good one. (I'm sure you know, but remember, Linux has the same 3GB limit in a 32-bit kernel as Windows. Obviously, 64-bit supports higher)

I agree with the others to go with an Nvidia card. It's just much more Linux friendly than ATI is. ATI has promised better support, but I'm not holding my breath. .

As for the Asus board that only supports 8GB... I didn't catch the model, but that sounds like a hardware limitation. I'd refer to the site. Normally what they list on their site is what the BOARD can take, not an OS or otherwise. If you have capital, go for the future proof board. We're not that far out from OEM desktops supporting 64GB of RAM. So, it's only a matter of time before all of that stuff is reasonably priced.

Regards,

Brandon