new machine -- memory bandwidth wanted

[mangrove]

I am in the process of building several new performance machines, but as building machines isn't my primary business, I am doing a little market research on components

The machines will be used for CFD, Computational Fluid Dynamics, meaning simulating how fluids/air/smoke/etc moves over a submarine hull/inside a building/in a tunnel/etc. This is a very computationally intensive task, and also very taxing on memory bandwidth.

Traditionally I have been building machines on the Intel platform, as many years ago the FP performance was much better and less years ago the chipset stability was way better. Now, I am considering AMD too.

So I am looking for platform hints, AMD or Intel. Requirements:
1) high stability. Any motherboard containing a vital component made by VIA disqualifies the product immediately. I am serious.
2) high memory bandwidth. With their integrated memory controllers, AMD should have the upper hand here -- right? For dual processor solutions, does a Xeon platform have higher bandwidth than A64/Opteron?
3) pure number crunching power. Athlon64? Opteron? Xeon? (only Windows compatible systems are interesting)
4) what is generally considered the best platform for AMD -- nVidia nForce or AMD's own chipsets (are there even products with these, still)? How about ATI, I have no experience at all with their chipsets?

So... any hints for me?

 

[MasterBaiter]

I would lean to Opterons @ this point for anything computational. As far as stability... well I can't tell you. I'd be inclined to go with an Nvidia Pro based motherboard because it's much more up to date than AMD's motherboard chipset offerings, but it's track record isn't proven yet in my eyes.

Video card related... I would probably be inclined to suggest an Nvidia professional product for OpenGL use. I'm using systems for AfterEffects and Maya. You may do okay with ATI, but we've run into issues from time to time with them, so we err on the side of safety now, and run Nvidia @ this point. :?


Here are some links to that may help:
http://www.gamepc.com/labs/view_content.asp?id=thunderk8we&page=1
http://www.gamepc.com/labs/view_content.asp?id=pciews&page=1
http://www.gamepc.com/labs/view_content.asp?id=asusnf4pro&page=1
http://www.gamepc.com/labs/view_content.asp?id=x36o252&page=1

http://www.linuxhardware.org/article.pl?sid=05/04/21/1747217&mode=thread
http://www.anandtech.com/IT/showdoc.aspx?i=2347
http://www.tomshardware.com/cpu/20040927/index.html

 

[arjan de lumens]

So I am looking for platform hints, AMD or Intel. Requirements:
1) high stability. Any motherboard containing a vital component made by VIA disqualifies the product immediately. I am serious.
2) high memory bandwidth. With their integrated memory controllers, AMD should have the upper hand here -- right? For dual processor solutions, does a Xeon platform have higher bandwidth than A64/Opteron?

The theoretical bandwidth of an 800FSB Pentium4 and a dual channel AMD64 processor with DDR400 memory should be the same - 6.4 GBytes/sec. In practice, the much lower memory latency of the AMD64 translates into considerably higher effectively usable bandwidth. Also, with Opteron processors, memory bandwidth scales with the number of processors you add, as every processor has a 128-bit memory bus and high-bandwidth interconnect between the processors (just make sure you get a board that is populated with DIMM slots for all the CPU sockets; some of the cheaper dual-Opteron boards only have DIMM slots to one processor). With the usual dual/quad Xeon boards, available bandwidth does NOT scale with the number of processors, as they share a single 800FSB bus.

3) pure number crunching power. Athlon64? Opteron? Xeon? (only Windows compatible systems are interesting)

Depends a bit on how well optimized the code is. If it is carefully hand-optimized, non-bandwidth-affected SSE code, the Xeon may perhaps have a slight edge in per-core performance. Otherwise go with the Opteron. You may also want to take into consideration that dual-core Opterons are available NOW, while dual-core Xeons are not planned to be released for a long time still.

4) what is generally considered the best platform for AMD -- nVidia nForce or AMD's own chipsets (are there even products with these, still)? How about ATI, I have no experience at all with their chipsets?

AMD's own chipsets seem to be popular with dual-Opteron boards, so I presume that they are of decent quality. Haven't heard a lot of complaints about NForce4 either.

 

[JCLW]

Tyan K8WE

 

[Blazkowicz]

for that kind of work a Cell workstation should be great
(but when will they be available?)

this kind of simulation has been done on GPUs (but I don't know if it's useful in real world engineering tasks )

 

[Pete]

Don't know how stable they are, but I believe ATI's MBs seem to offer the most bandwidth nowadays, at least with the synthetic benchmarks used to test that sort of thing.

For your (FP performance) needs, mangrove, I believe dual-core Opterons would be ideal if you had the budget for them. Otherwise, maybe socket 939 MBs with an eye toward a dual-core upgrade in the future, if you need the extra power.

 

[{Sniping}Waste]

I know you said no VIA but The VIA K8 chipsets are some of the best stable chipsets out there. I won't use a VIA K7 of P4 chipset but would use a K8 chipset any day. From expereans and info from others the Nforce K8 chipset are on the bottom for stablilaty but are the thing for OCing. I have a Asus VIA based motherboard with 3000+ and have no problems with it. Its been running 24/7 for over 5 months with out a shutdown or reset doing games, suffing, and multi media work (if thats not stable then I don't know what is).
The VIA, AMD, SIS, and ATI chipsets are faster and more stable the the Nforce3 and 4 at stock speeds.

For what you want to do you will want a duel Optron so take a look at Tyan duel motherboars and see if theres one you like for the price.

 

[mangrove]

I would lean to Opterons @ this point for anything computational. As far as stability... well I can't tell you. I'd be inclined to go with an Nvidia Pro based motherboard because it's much more up to date than AMD's motherboard chipset offerings, but it's track record isn't proven yet in my eyes.

Thanks. Differences between Opteron and Athlon64? The fastest single A64 CPU available is the 4000+ (2400MHz). The only affordable Opteron solution would be two 1800MHz 244s; with normal SMP inefficency, I'm not all that sure I will benefit much... or what do you think?

Video card related... I would probably be inclined to suggest an Nvidia professional product for OpenGL use.

Luckily, graphics isn't an issue with the usage patterns the machine will see; wireframes and occasional flat shading, that's the toughest part. I bet integrated graphics will suffice, but I'll go for a middle-of-the-road gaming solution that's passively cooled...

 

[mangrove]

for that kind of work a Cell workstation should be great
(but when will they be available?)

A fantastic quote.

Aside from that, I remain a little sceptical that the creators of software in the $100'000 class, stuff used for very serious engineering projects, should port it to a console.

 

[mangrove]

For your (FP performance) needs, mangrove, I believe dual-core Opterons would be ideal if you had the budget for them. Otherwise, maybe socket 939 MBs with an eye toward a dual-core upgrade in the future, if you need the extra power.

Thanks (and also thanks to arjan de lumens). Yes, Opterons seems nice -- one of the previous machines I built was a dual Xeon 3.06, a disappointment in many respects... unfortunately, Opterons aren't cheap or plentiful, and the same goes for the motherboards. And Tyan, always the best choice, isn't the most common brand over here (Sweden) -- in fact, almost everything else is more common

I have some serious thinking and discussion to do... but I really appreciate the input. Exactly the sort I wanted.

 

[mangrove]

I know you said no VIA but

The members of the VIA chipset division should be sodomized with their own worthless products, their engineers afterwards scattered all over the world to do something meaningful with their lives. The management should be fed to ogres.

I hope I have made my standpoint on VIA clear.

 

[suryad]

Wow I thought the KT800 or whatever its called is a superb product...Sinping Waste already mentioned it in this forum. And IIRC they are manufactured by VIA...why are you so negative about those fellas??

 

[Guden Oden]

Differences between Opteron and Athlon64?

None, apart from A64s can't be used in a multiprocessing environment. Opteron is designed for two to eight CPUs/system.

The fastest single A64 CPU available is the 4000+ (2400MHz). The only affordable Opteron solution would be two 1800MHz 244s; with normal SMP inefficency, I'm not all that sure I will benefit much...

So why not start with a dual processor opteron mobo with one fast processor and then populate the other CPU socket later when you got more cash to spend? If you go A64, you'll be stuck forever with one socket which won't give you much room to grow into...

but I'll go for a middle-of-the-road gaming solution that's passively cooled...

ATI Radeon X200 PCIe. Surprisingly fast despite how low-specced it is. Particulary the version with 128-bit onboard memory should suit you very well.

 

[mangrove]

why are you so negative about those fellas??

Let's just say I've played in this field for far too long... and seen far too many broken products from them, often broken in very subtle ways almost impossible to diagnose. Never, ever more, even if I get the crap for free. Heck, I'll PAY to avoid VIA.

For each his own, of course.

 

[mangrove]

None, apart from A64s can't be used in a multiprocessing environment. Opteron is designed for two to eight CPUs/system.

Ah, a forced market segmentation

So why not start with a dual processor opteron mobo with one fast processor and then populate the other CPU socket later when you got more cash to spend? If you go A64, you'll be stuck forever with one socket which won't give you much room to grow into...

After doing some testing today, the main application running on this machine is going to be embarassingly single-threaded for the foreseeable future, but with options (weak) for clustering. I am leaning heavily towards single proc -- in fact, I am pretty much decided -- but thanks for the viewpoint, which of course makes sense!

Today's testing also decided that the machine is going to have 4 gigs of PC3200 RAM. That upped the price a bit

ATI Radeon X200 PCIe. Surprisingly fast despite how low-specced it is. Particulary the version with 128-bit onboard memory should suit you very well.

You mean the X300? I think I'm more of a 700 guy

 

[mangrove]

And AMD was chosen

I ordered the machines today... two of them. Athlon64 4000+, Raptor as system disk and two mirrored 7200rpm WD disks as storage. And, um, 4 gigs of RAM I think it will suffice.

 

[{Sniping}Waste]

Re: And AMD was chosen

I ordered the machines today... two of them. Athlon64 4000+, Raptor as system disk and two mirrored 7200rpm WD disks as storage. And, um, 4 gigs of RAM I think it will suffice.

What mobo are you going to use?

 

[mangrove]

Re: And AMD was chosen

What mobo are you going to use?

Asus A8N-E