mersenneforum.org Hardware choice frustrations...is it just me?
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 2008-06-29, 02:02 #1 larrylogory   Jun 2008 3 Posts Hardware choice frustrations...is it just me? As someone interested in building a modern, dedicated system to run prime95, I'm finding the whole thing darn frustrating. Every time I think I have a way forward I read a post that mentions all sorts of negative issues ranging from FSB speeds, to cache size, to memory speed, to certain mobos not liking something and going unstable. I want to build a dedicated system (or systems) and maximize my bang for the buck, and I keep flopping between a modern four-core system and two (or more) older dual-core systems. For the modern option, I get hooked into the “more is better” logic, and before I know it I'm considering hardware that, while very fast, pushes modern limits so far that they appear to suffer from reliability and compatibility problems. While the specs read great, user experiences scare me a bit. For the older/cheaper option, one first has to deal with all the redundancy (two power supplies, two hard drives, two ...) and then tolerate the painstakingly slow interconnects. While I appreciate the performance numbers that people post--as they do sometimes reveal interesting choke points--the degrees of freedom are so large that none of you are using the identical hardware! It’s been a fun learning process, but I sure wish the choice was more obvious.
 2008-06-29, 07:14 #2 lavalamp     Oct 2007 Manchester, UK 2×3×227 Posts Basically, you'll get the best bang for your buck by having as many CPU cores as possible with as few other componants as possible. In other words, 1 dual processor motherboard and 2 quad core CPUs. There are also quad processor mobos but the price increase there makes them less financially attractive than the dual processor boards. Intel CPUs perform the best in LLR tests, but you may only get 3/4 cores worth of crunching running LLR on all cores. The next generation of Intel chips, which will be native quad core designs, will be much better in that respect and give closer to full performance on all cores. If you were to go with the current crop of quad cores then you could run LLR on three of the four cores in each CPU, and run trial factoring or some other less memory bandwidth intensive test on the other. Graphics cards, while good for 32 bit floating point arithmetic, lick balls when it comes to the 64 bit arithmetic required for LLR tests, hence you'd be better off not getting one of those just yet until they support it natively. However there are some applications which can take advantage of 32 bit graphics cards such as folding@home, so if you want to run that I believe ATi cards are better supported in that arena. As far as other componants, you need a decent, but not massive, amount of RAM for LLR tests. The important thing is that it's fast, which can conflict with using a dual socket motherboard, as those usually require fully buffered DIMMs which add to the latency. EEC RAM would also perhaps be worth while as it will detect and fix any read/write errors on the fly. If you do run trial factoring on two cores, the RAM requirement will go up, so aim for 4GB minimum with that, though 8GB would be better. For hard drive you could leave one out entirely and boot over the network, or you could install a barebones OS to a compact flash card connected to an IDE converter, or you could just hook up a small and cheap HDD. CD and/or floppy drove wouldn't be necessary, but might occasionally be useful depending on the setup. Personally I like to include a CD and Floppy drive in all my PCs just because they're so cheap. No need to go overboard with dual redundant PSUs or anything like that, but make sure not to skimp on it. Get a good brand like Seasonic or Enermax or PC Power & Cooling, or any number of other top name brands. Get a power bracket far above what you will use, since that way the PSU is taxed as little as possible, perhaps a minimum of 600W. At the very least a surgemaster would be required to protect your expensive equipment, and I also recommend a UPS too so that they can easily ride through a brown-out or even a short black-out. Even though a UPS may claim to have surge protection, you should still get a surge protector anyway, at the very least you can use it to give yourself more UPS plug sockets. A sturdy well designed case is also a must, but don't go overboard. I find that although steel cases are quite a bit heavier, they are much stronger than aluminium. Make sure that it has enough places to mount 120mm fans to cool componants, that's very important since it will be run at 100% all the time. At least one in the front and one in the back, two in the back would be better, and if it has space for a blow-hole fan, better still. 19" rackmount cases tend to be uneccesarily expensive and generally have poorer airflow due to being thinner which means they need more, smaller, louder fans. The airflow is less of an issue with 3U and 4U cases though. To squeeze the most out of your system, you may also wish to splash out on aftermarket air or perhaps even water cooling. Think of overclocking as a free performance boost. It can often be a lot cheaper to get a mid-range CPU and overclock it to be as good as, or better, than the top end CPU. This is especially true with Intels latest which seem to be very good clockers. The down side is that this process involves a lot of trial and error, and you have to be absolutely certain that your PC is stable.
 2008-06-29, 08:29 #3 Uncwilly 6809 > 6502     """"""""""""""""""" Aug 2003 101×103 Posts 3×47×71 Posts If you are looking to a single machine, lavalamp's answer is good. If you are looking to build a farm or monster look here: http://web.archive.org/web/200308010...com/index.html and to one of the links: http://web.archive.org/web/200207021...n.html#addcomp Attached Thumbnails
2008-06-29, 13:26   #4
fivemack
(loop (#_fork))

Feb 2006
Cambridge, England

11001001010012 Posts

Quote:
 Originally Posted by lavalamp Basically, you'll get the best bang for your buck by having as many CPU cores as possible with as few other componants as possible. In other words, 1 dual processor motherboard and 2 quad core CPUs. There are also quad processor mobos but the price increase there makes them less financially attractive than the dual processor boards.
I think you're wrong there; the dual-processor motherboard costs more than two single-processor motherboards plus an extra case, which is what it would be replacing, and the dual-processor-capable CPUs cost a good deal more than the single-processor ones (the premium's enormous for AMD and about 20% for Intel)

Or has the market changed again since the last time I looked?

 2008-06-29, 16:50 #5 mdettweiler A Sunny Moo     Aug 2007 USA (GMT-5) 3×2,083 Posts A little while back I posted some parts lists for some good maximum-bang-for-the-buck quadcore crunchers on the Free-DC forum--you can check it out here. The Intel configuration listed can also be configured with a Q6600 (in fact, that's what I would recommend).
 2008-06-29, 17:10 #6 dsouza123     Sep 2002 2·331 Posts Or holding off until Intel releases Nehalem based CPUs at the end of 2008 / start of 2009, that use CSI/Quickpath Interconnect (Intel's answer to AMD's HyperTransport) instead of FSB, which should greatly increase bandwidth and lower latency which should be good for LL. The quad core CPUs will be refinements of current Core 2 Quads except having shared L3 and QuickPath. http://realworldtech.com/page.cfm?Ar...WT040208182719
 2008-06-29, 18:17 #7 lavalamp     Oct 2007 Manchester, UK 2·3·227 Posts I just put together a quick list of componants for a dual CPU and a single CPU system. It seems that for decent systems, two single CPU machines would be slightly more expensive. However they may also give slightly better performance. However again, they will also consume more power. I guess it depends what you're looking for and how much money you want to spend. One dual CPU machine will perhaps be easier to manage, more energy efficient, easier to transport, and be a lot more resiliant to memory errors (EEC FB-DIMMs). Two dual CPU machines will be a little more power hungry, require twice the setup time, but may give better performance and will certainly be easier to overclock. It may well be better to go with the single CPU machine then, since you will have a wider choice of parts and probably get better driver support on Linux (if you run Linux that is). Personally, if I had the money I think I would go for a dual Xeon machine, if only because that'd be one box in the corner, not two. However no matter which you choose, it would still be a really good idea to wait until Intel release their first wave of Nehalem core CPUs which will be natively quad core, instead of double dual core like the current crop.
 2008-06-29, 20:36 #8 IronBits I ♥ BOINC!     Oct 2002 Glendale, AZ. (USA) 111310 Posts Or wait another year past the release, so the prices for the CPUs are much more reasonable. Last fiddled with by IronBits on 2008-06-29 at 20:36
 2008-06-29, 20:51 #9 lavalamp     Oct 2007 Manchester, UK 101010100102 Posts There's no point waiting a whole year, if you do that there's a new top of the range out. It's only worth waiting when there's a new crop about to be released.
2008-06-29, 22:17   #10
fivemack
(loop (#_fork))

Feb 2006
Cambridge, England

3·19·113 Posts

Quote:
 Originally Posted by lavalamp I just put together a quick list of componants for a dual CPU and a single CPU system. It seems that for decent systems, two single CPU machines would be slightly more expensive. However they may also give slightly better performance. However again, they will also consume more power.
I'd be interested to see the list of components you use; using newegg.com I make two single-processor computers a lot cheaper than one dual-processor one.

E5410=$275 x2, DSAN-DX motherboard which is the cheapest I can see for dual-Xeon is$300, these are crunchers so you don't need a hard disc (boot from $10 USB stick) and the motherboard has onboard graphics, so that's$860 + case + RAM, and the board uses DDR2 so the RAM would be the same whether it's distributed over one or two computers.

Q6600=$200, P5B-VM motherboard is$80, USB stick is still $10, so two of those is$580 + two cases + RAM; a case doesn't cost three hundred dollars.

Quote:
 However no matter which you choose, it would still be a really good idea to wait until Intel release their first wave of Nehalem core CPUs which will be natively quad core, instead of double dual core like the current crop.
I will be very surprised if first-wave Nehalems are competitive price-performance with the same price in Q6600 systems; the impression I get is that they are launched into the same market as Skulltrail boards are now, you'll be paying $2500 for a board, two high-end Nehalems which are the only ones that will be available, and six DDR2 sticks. A cruncher system needs a$100 integrated-graphics motherboard plus the best price-performance processor which that supports; I think that's still Q6600.

2008-06-29, 22:20   #11
fivemack
(loop (#_fork))

Feb 2006
Cambridge, England

11001001010012 Posts

Quote:
 Originally Posted by Anonymous A little while back I posted some parts lists for some good maximum-bang-for-the-buck quadcore crunchers on the Free-DC forum--you can check it out here. The Intel configuration listed can also be configured with a Q6600 (in fact, that's what I would recommend).
Why do you equip your crunchers with a hard disc drive? Ubuntu fits happily on a 2GB USB stick, and current motherboards boot from those without trouble - indeed, I've just sold a system which I've used as a cruncher for eighteen months, and the purchasers have found that it's having lots of trouble with its PATA controller, which I never encountered since the machine has no disc.

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