Which of these CPUs is most productive?

[lavalamp]

Basically, you pick the motherboard you want first, then you worry about a case. If you pick a μATX motherboard then you have the option of also picking a smaller case. You can pick the case first of course, but if you pick a small one it limits your choice of components.

For desktops the main two motherboard form factors you're likely to run into are ATX and Micro ATX (aka μATX or uATX). If a case is large enough to accomodate an ATX motherboard, it can also accomodate a μATX motherboard, and they share many of the same mounting points. The reverse is not necessarily true though.

μATX boards have three fewer expansion slots on the bottom, so they are physically shorter. Some very large cases can also accomodate larger EATX motherboards, but these are generally server or skulltrail boards (the skulltrail platform is essentially a server platform dressed up to appeal to gamers). You can get some non-server/skulltrail motherboards that are EATX, but they are very expensive.

Intel tried to push BTX a while back, it's pretty similar to ATX but with a few tweaks, and it seems to have died now.

There are also many small form factors like mini/nano/pico-ITX, DTX etc. These are pretty small, just a glance at them is enough to see how small, the ports on the back barely fit along the edge. If you're building a system with one of these in then you need to pay a lot more attention to what form factors the case can support.

The power supply can also be a tricky one, you have to make sure you know exactly what power sockets your motherboard has. This is usually a large 24 pin ATX connector, and then either a 4 pin or 8 pin connector near the CPU. Beefy graphics cards also have special power sockets on them, 6 pin, 8 pin, two 6 pin or 6 pin and 8pin are all common configurations. You MUST make sure your power supply has the right plugs for the job and actually has enough overhead to supply the juice.

[Rodrigo]

@Mini-Geek
@lavalamp

It sounds like matching up a motherboard with a case is not as complicated as I'd thought. Thanks for filling me in!

Rodrigo

[mdettweiler]

Originally Posted by Rodrigo

I looked up the AMD six-cores. I didn't know about the overclocking capability (or lack of it), but FWIW besides the price they also seem to have different clock speeds (3.2/3.0/2.8 GHz). I'm not sure how much of a difference that would make for the purposes of GIMPS.

It can be a little hard to compare clock speed between AMDs and Intels; also, while clock speed definitely does have an effect with GIMPS, cache size is also quite important. So what I did for each CPU I've discussed above is look it (or a similar model if the exact one is not listed) up on the PrimeNet benchmarks site to see how well they do on LL iteration timings.

Unfortunately, there aren't many Sandy Bridge benchmarks up on PrimeNet yet, so it's a little hard to compare there. However, assuming a 25% speed boost over a comparable previous-generation i5 or i7 (respectively), since that's what people have been reporting in other threads, it would still not be enough to make one Sandy Bridge quad equal one Phenom II X6.

[Flatlander]

Also depends on how much things overclock, if you are going down that route.
(Forgive me if that has been covered, I didn't read all the thread. )

[Rodrigo]

Originally Posted by mdettweiler

assuming a 25% speed boost over a comparable previous-generation i5 or i7 (respectively), since that's what people have been reporting in other threads, it would still not be enough to make one Sandy Bridge quad equal one Phenom II X6.

mdettweiler,

That is truly remarkable -- despite a "new generation" of ballyhooed Sandy Bridge processors, it sounds like AMD still cleans Intel's clock (so to speak) when it comes to GIMPS.

AMD is looking more and more attractive for my next system! I've always had "Intel inside," but it's getting harder to justify it.

We'll see what the upcoming AMD chips have to offer in the way of productivity.

Rodrigo

[axn]

Originally Posted by Rodrigo

That is truly remarkable -- despite a "new generation" of ballyhooed Sandy Bridge processors, it sounds like AMD still cleans Intel's clock (so to speak) when it comes to GIMPS

apples-to-oranges. six cores vs 4. and once p95 is rewritten using avx, the performance could potentially double for sandy bridge (although, in practice, you might see another 30% improvement?) -- keep that in mind.

[Christenson]

Lava Lamp and Dettweiler, thank you both. I'm at the point of buying my next compute box. I'm not terribly interested in fooling with the overclocking, much more interested in basic reliability and more or less maintenance-free operation.

If I buy a pre-assembled box, I'm thinking the Phenom II x6 is the way to go, with each core doing a worker thread for Prime95. But the pricing on assembling my own box is pretty interesting....but I'm not familiar with how to get Windoesn't onto a new system like this, and am having trouble making a backup hard drive of an old copy of XP at the moment. And if you want two systems under my desk for that grand, I'll want to do it with just one copy of Windoesn't..the other will run Linux once it's up. So, help with getting Windoesn't onto the new system, please....and thanks...

[mdettweiler]

Originally Posted by axn

apples-to-oranges. six cores vs 4. and once p95 is rewritten using avx, the performance could potentially double for sandy bridge (although, in practice, you might see another 30% improvement?) -- keep that in mind.

Hmm, interesting...I didn't realize the performance boost from AVX would be quite that much. In that case, the additional 30%*4 cores would end up giving you "another core" (effectively) compared to the AMD, and the Sandy Bridge would beat the X6 by a little bit in terms of overall throughput. (That's assuming the 30% improvement that you estimated...though as you said it could potentially be greater.)

I'd still go with the X6 right now since they would be about the same in the long run, and other applications (not just Prime95) could reap the benefits of the increased throughput as well. But it does look like it will be more of a tossup in the future.

What will be particularly interesting is when AMD's Bulldozer 8-core processors come out...from the way things are shaping up, I'd say there's a fairly good chance that AMD will once again take the lead in overall-throughput-per-$ considerations. The big question will be how cheaply they start them out at, and how quickly the prices drop from release levels. Intel rather interestingly worked the Sandy Bridge processors into its existing i5/i7 price tiering quite seamlessly, such that there was no "initial price spike"--perhaps AMD will do the same to compete.

Originally Posted by Christenson

If I buy a pre-assembled box, I'm thinking the Phenom II x6 is the way to go, with each core doing a worker thread for Prime95. But the pricing on assembling my own box is pretty interesting....but I'm not familiar with how to get Windoesn't onto a new system like this, and am having trouble making a backup hard drive of an old copy of XP at the moment. And if you want two systems under my desk for that grand, I'll want to do it with just one copy of Windoesn't..the other will run Linux once it's up. So, help with getting Windoesn't onto the new system, please....and thanks...

Installing Windows on a new system is pretty simple. Just buy the install DVD (you can get an OEM copy on Newegg for $100), and once you've built/bought the computer, boot it up and pop the disc in the drive. (You'll want to do this quickly, before the BIOS checks the CD drive and finds nothing there...but even if that happens before you get to finish putting in the CD, just turn it off and back on again.) It will boot directly into the installer, which is pretty straightforward.

They actually have a video walkthrough of the install on the Newegg product page I linked to--not sure how useful that would be but it might help.

[Rodrigo]

Originally Posted by Christenson

If I buy a pre-assembled box, I'm thinking the Phenom II x6 is the way to go, with each core doing a worker thread for Prime95. But the pricing on assembling my own box is pretty interesting....but I'm not familiar with how to get Windoesn't onto a new system like this, and am having trouble making a backup hard drive of an old copy of XP at the moment. And if you want two systems under my desk for that grand, I'll want to do it with just one copy of Windoesn't..the other will run Linux once it's up. So, help with getting Windoesn't onto the new system, please....and thanks...

Christenson,

If you don't have an XP installation disc, you might try creating an image of your existing installation for the purpose of porting it to a new HDD. But you also report having trouble making a backup. Do you know what's going on with the drive? Is it a problem with the drive itself? In that case, a program like SpinRite (paid, sorry) might be able to help you to save the disk, at least for long enough to image it.

These links might also help with installing XP:
http://ask-leo.com/i_dont_have_an_in..._need_one.html
http://www.brighthub.com/computing/w...les/50115.aspx

Good luck. I agree with you that the AMD Phenom II X6 is looking pretty interesting.

Rodrigo

[mdettweiler]

Originally Posted by Rodrigo

Christenson,

If you don't have an XP installation disc, you might try creating an image of your existing installation for the purpose of porting it to a new HDD. But you also report having trouble making a backup. Do you know what's going on with the drive? Is it a problem with the drive itself? In that case, a program like SpinRite (paid, sorry) might be able to help you to save the disk, at least for long enough to image it.

These links might also help with installing XP:
http://ask-leo.com/i_dont_have_an_in..._need_one.html
http://www.brighthub.com/computing/w...les/50115.aspx

Good luck. I agree with you that the AMD Phenom II X6 is looking pretty interesting.

Rodrigo

Hmm...it seems that those links mainly refer to reinstalling XP on a system that already has it installed when you don't have a CD on hand. The procedure documented therein would not work for a computer with no operating system. (Though it might work if the computer had an earlier version of Windows installed...it might be a little messy but it would still work. Come to think of it, I did something similar when I upgraded a laptop from 98 to 2000 a while back. It worked, but I ended up with a weird same-partion dual-boot setup. )

As far as copying a drive image of an existing XP setup, that will only work if the new hard drive is to be used in the same computer (or a nearly-identical one): Windows will give a BSOD on bootup if the hard drive controller it's running on is not the one it was intalled with. (In other words, if you have a different model motherboard.)

Christenson, your best bet will probably be to get a new Windows installation CD for the new computer and install that (as I described in my last post). If you have a retail copy of Windows XP sitting around somewhere that's not installed on any computers, you can use its CD and license key to install XP on the new computer. (Note that OEM, i.e. manufacturer-preinstalled, Windows licenses cannot be transferred from the computer they came with, so a reinstall CD for another prebuilt computer will probably not be any good.)

[Rodrigo]

mdettweiler,

Good points all.

We would need more information from Christenson as to his situation in order to provide better guidance. I offered those links in case they were relevant to his circumstances.

No question that the best solution is to buy an XP CD if he doesn't have one already, although I gather that he's trying to limit the expenses on the new builds.

He said that he's trying to back up a hard drive with an old copy of XP, which I'm guessing is how he would like to get that operating system. XP isn't the OS I'm most familiar with, but I have reinstalled Windows 98 fresh onto new hard disks. Win98 has a .CAB file folder with all the installation files: It sounds like that i386 folder with the winnt32.exe file might be the analogous resource for an XP installation, in which case he may be able to copy that and use it.

But of course I could be wrong. (Correct me, please!) Anyway, my idea was that if the situation is that Christenson has XP on a failing hard drive, then he might be able to salvage that installation folder and do a fresh installation off it. Once again, though, we could use more details.

Rodrigo