Best Unit for the Job?

[xkey]

Originally Posted by Primeinator

Linux 64-bit is what I'm thinking. I've heard Prime95 is faster on Linux anyway.



Yes, sorry. I should have indicated where I lived. I'm in the central United States.

So how much performance difference is there between the i7 920 and Q6700? Is the 6700 a 64-bit compatible CPU?

The core i7s see an "appreciable" performance boost on multi-threaded apps.

It is difficult to quantify in general but let's just toss out a 'sane range' of 20-50% performance boost for an i7 with fast ddr3 dram over a Q6700 with fast ddr2 dram on a typical cpu bound multi-threaded app. As someone has earlier pointed out the D0 steppings of the 920 apparently overclock very well. [ you can go read up on coolers & overclocking here - http://forums.extremeoverclocking.co...splay.php?f=84 ]

It goes without mention that some of the performance boost in going with a core i7 comes from memory interface aspects - i'm pretty sure unless i have overlooked some niche quad core moboard that slots the Q6xxx series chips & their pinouts that they all had a FSB. The moboard memory interface for the core i7s utilize Quick Path Interconnect.

The core i7 is a superior performer over phenom II for your intended use at this point in time. The AMD istanbuls with 6 cores are on par with the multithreaded nehalems ... but are more costly right now than the 920 [and who is to say that with the short time from 1st tape out to mass production that there are not too many undiscovered bugs in the istanbuls]

C++ya,
cout << "xkey" << endl;

[joblack]

I suggest to get the price worthy choice - means a Qxxxx quad core.

The Core i7 is a only a choice for ultra rich people with no other problems in life.

[CRGreathouse]

Originally Posted by joblack

The Core i7 is a only a choice for ultra rich people with no other problems in life.

Not really. The Qxxxx series you suggest ranges from $160 to $350 on Newegg. The i7 920 is $270. Yes, the motherboards are more expensive, but they're not *that* bad.

[lavalamp]

Don't forget that the only desktop Nehalem CPUs out now are the Bloomfield high end i7s. Soon there will be mid-range 45nm Lynnfield and low-end 32nm Clarkdale chips on socket LGA-1156.

As I understand it, for that socket there will be i5s (at 45nm) released in 2 or 3 months, i3s (at 32nm) released in 5 or 6 months and i7s (at 45nm) released next year, they will still take DDR3 RAM, but won't use QPI and have only dual channel memory.

Here's a quick key to show what the number after the i means:

i9 = six cores, 12 threads (not yet released, but will be for the high end and servers)
i7 = four cores, eight threads
i5 = four cores, four threads (no hyperthreading)
i3 = two cores, four threads

[henryzz]

Originally Posted by lavalamp

but won't use QPI and have only dual channel memory.

which wont?
is it all the new i3s, i5s, i7s and i9s?
i would be surprised if the i9s didnt use QPI as it looks like a step back unless there is something new
edit: do you have any good links hand for finding this sort of thing?
googling has never worked very well for me for this type of subject

[lavalamp]

CPUs released on socket LGA-1156 will not use QPI. Those i3, i5 and i7 chips I mentioned in the coming months are for socket LGA-1156. Since the i9 is for high end, and LGA-1156 is distinctly not high end, the i9 chips will be on socket LGA-1366 for desktops and will have QPI.

As for finding stuff out, I just read a lot of tech sites and occasional press releases. If you're interested in tech then checkout Toms Hardware, [H]ard|OCP and AnandTech and basically anyone they link to.

[petrw1]

http://www.itworldcanada.com/Pages/D...c71&sub=490495

AMD plans to launch later this quarter, an ultra low power Istanbul version of its Opteron EE offering. And, AMD has also said its 12-core Magny-Cours processor is slated for a 2010 release.

[joblack]

Originally Posted by CRGreathouse

Not really. The Qxxxx series you suggest ranges from $160 to $350 on Newegg. The i7 920 is $270. Yes, the motherboards are more expensive, but they're not *that* bad.

You can get a quite good mainboard around 36 Euro (VGA included) - 2 x 2 GByte DDR2 - 800 around 38 Euro. The mainboards for the Core i7 are at least around 200 Euro and the memory (DDR3) is more expensive.

The question is if you want to have the most performance for GIMPS or for yourself (for instance you want to play hightech games, ...) - they aren't mutual exclusive so it's a matter of personal taste.

For the first I suggest get two or three of the E5400 (overclock them) + Mainboards and you have much more power for the same price ...

[CRGreathouse]

The i7 motherboards should cost well less than 200 euro, or you're getting ripped off. I could get them for less the last time (maybe 4-6 months ago) I was looking, and prices have surely fallen since.

But I don't disagree with your analysis. I chose a Phenom II rather than an i7 because of the cost of the motherboard.

[joblack]

Originally Posted by CRGreathouse

The i7 motherboards should cost well less than 200 euro, or you're getting ripped off. I could get them for less the last time (maybe 4-6 months ago) I was looking, and prices have surely fallen since.

But I don't disagree with your analysis. I chose a Phenom II rather than an i7 because of the cost of the motherboard.

You're right - the price got down but is still around twice as much as an expensive Qxxx mainboard. The earlier Phenom had some problems with the TLB, today it might have more fun.

The fun thing for a i7 (Nehalem) is the the Hyperthreading and would be my first choice to hunt 100M primes ... but only for that reason ... ;).

[CRGreathouse]

Originally Posted by joblack

The earlier Phenom had some problems with the TLB, today it might have more fun.

The Phenom was terrible. The Phenom II is great -- better than I expected.