CPU Swap Q?
 

Hey guys! I have an old desktop (~5 y.o.) that has a GTX 460 running mfaktc off and on. I have trouble utilizing the full potential of the GPU due to using my Pentium D 940, which cannot feed it fast enough to make full use of the GPU. Is there any CPU I can upgrade to without having to switch the mobo and all that [B]which would be able to feed the GPU fully[/B]?
Suggestions, comments, and/or bunnies with pancakes accepted!

[QUOTE=c10ck3r;310423]Hey guys! I have an old desktop (~5 y.o.) that has a GTX 460 running mfaktc off and on. I have trouble utilizing the full potential of the GPU due to using my Pentium D 940, which cannot feed it fast enough to make full use of the GPU. Is there any CPU I can upgrade to without having to switch the mobo[/QUOTE]

Not even close. The socket in which the CPU sits changes with each architecture, which for Intel has been every two years. [URL="http://ark.intel.com/products/27519/Intel-Pentium-D-Processor-940-(4M-Cache-3_20-GHz-800-MHz-FSB)"]Your socket is PLGA775[/URL]; first generation Core i* processors (Nehalem/Westmere) used LGA1156, and the current generation Sandy/Ivy Bridge processors use LGA1155. (I believe Haswell/Broadwell will use LGA1150.)

[url]http://en.wikipedia.org/wiki/File:IntelProcessorRoadmap-3.svg[/url]

Going to depend on motherboard (VRM and BIOS versions); some 775 boards will take up to Core2Quad processors.
Whether that is enough of an upgrade to feed a 460 IDK; no nvidia here.

[QUOTE=c10ck3r;310423]Hey guys! I have an old desktop (~5 y.o.) that has a GTX 460 running mfaktc off and on. I have trouble utilizing the full potential of the GPU due to using my Pentium D 940, which cannot feed it fast enough to make full use of the GPU. Is there any CPU I can upgrade to without having to switch the mobo and all that [B]which would be able to feed the GPU fully[/B]?
Suggestions, comments, and/or bunnies with pancakes accepted![/QUOTE]

Are you willing to work on small Fermat numbers or the double Mersennes (MM61, MM89, MM107, and my favorite MM127)?

If so, I'll have an mfaktc variant that can test those numbers doing all sieving on the GPU. It should be ready for testing within a week.

BTW, MM127 has no factors less than 2^176 (I retested 2^169 to 2^176). I'm 80% done through 2^177. Nineteen days after that I'll have tested through 2^178. Rcv is testing 2^178 to 2^179 at the same time.

A little poking around suggests that Core2 Duo and Quad CPUs use LGA 775.

Quad example:
[URL]http://ark.intel.com/products/35428/Intel-Core2-Quad-Processor-Q9650-12M-Cache-3_00-GHz-1333-MHz-FSB[/URL]

This thread discusses replacing the D940 with a Core 2 Duo E8400:

[URL]http://forums.extremeoverclocking.com/t286218.html[/URL]

The catch is that you would need to know that your BIOS can be updated to support Core2. It appears that the Core2 would use less power than the D940.

If you search "Pentium D940 replacement" lots of hits come up. I ran across a Tom's Hardware discussion that I can't find my way back to, but it allowed of the possibility on SOME boards.

I do assume that you are already running 2x mfaktc. What is the motherboard make and model?


EDIT: What I've read suggests that the Core2's are substantially faster than the Pentium D's, clock for clock. Some people here are running Core2 Quads. Perhaps they can weigh in on their capabilities.

[QUOTE=kladner;310431]What I've read suggests that the Core2's are substantially faster than the Pentium D's, clock for clock. Some people here are running Core2 Quads. Perhaps they can weigh in on their capabilities.[/QUOTE]

And the current Britches are substantially faster than the Core2s, clock for clock... :cmd:

[QUOTE=Dubslow;310432]And the current Britches are substantially faster than the Core2s, clock for clock... :cmd:[/QUOTE]
Huh? :huh:

[QUOTE=kladner;310434]Huh? :huh:[/QUOTE]

Clock speed isn't everything for speed :max:
For the best example look at AMD BD.

[QUOTE=kladner;310434]Huh? :huh:[/QUOTE]
Bridges. SB and IB.
[QUOTE=kracker;310435]Clock speed isn't everything for speed :max:
For the best example look at AMD BD.[/QUOTE]
:missingteeth:

Yessir, m'lord
 

[QUOTE=Prime95;310429]Are you willing to work on small Fermat numbers or the double Mersennes (MM61, MM89, MM107, and my favorite MM127)?

If so, I'll have an mfaktc variant that can test those numbers doing all sieving on the GPU. It should be ready for testing within a week.

BTW, MM127 has no factors less than 2^176 (I retested 2^169 to 2^176). I'm 80% done through 2^177. Nineteen days after that I'll have tested through 2^178. Rcv is testing 2^178 to 2^179 at the same time.[/QUOTE]
I would [U]definitely[/U] be interested in the Fermat variant of mfaktc. I ran a couple ranges on CPU in cahoots with fermatsearch.org, and enjoy this kind of work (in addition to P-1 and LLRing riesel and sierpinski(sp).)

[QUOTE=Dubslow;310436]Bridges. SB and IB.

:missingteeth:[/QUOTE]

O.....K. I'm just not quick enough. Of course they are much more powerful. But the OP wants to stick with the current MB.

Hi,

just wait for mfaktc 0.20.

Oliver

[QUOTE=TheJudger;310461]Hi,

just wait for mfaktc 0.20.

Oliver[/QUOTE]

Eagerly!

@OP: before doing any step in replacing your CPU, you have to check if your mobo supports Duo and Quad CPUs. Socket 775 can be "dedicated" to single, dual or quad chips, i.e. old mobos done with ViA or SiS chipsets can support Pentium4 (the socket 775 version) or PentiumD single and dual core, but not Core2Duo or Quad (socket 775).

Look to Asus web page for example, select mobo/socket775/via/sis chipsets, and see they specify for each mobo if it supports core 2 dual/quad chips or not.

Core2Duo is MUCH faster than the Pentium D 940 you have. In fact, looking to intel site, any of [URL="http://ark.intel.com/products/family/34522"]this[/URL], [URL="http://ark.intel.com/products/family/28398/Intel-Core2-Quad-Desktop-Processor/desktop"]this[/URL], or [URL="http://ark.intel.com/products/family/26547"]this[/URL], is much faster then you already have, and most of them are still active (i.e. they are not "end of life" or "end of intel support" if you look to the status column).

I still use a couple of them. In fact, I am writing this post from an E7400. I have one E7400 (2.8GHz Core2Duo socket 775) rusting around, which I assume is still fully functional, from one of my old comps, whose mobo was fried by a thunder. No joke, during a thunderstorm, the telephone line was hit, my modem/router burned, all serial ports and usb ports on the mobo, agp and one hdd, gone. The mobo (asus p5vdc-mx, with via p4m800 pro chipset) still can be used with on-board graphic chip, seems the cpu and both memory slots survived, it should be somewhere in the storage closet, full covered by dust. I plan to replace the mobo, but this plan did not materialize since months...

You may also use a faster memory, if you change the CPU. The Pentium D 940 has a 800MHz FSB, but all the core 2 thingies go much higher, like 1066MHz, 1333MHz
.

Great details! :goodposting:

I don't want to be a nay-saying anti-bunny-with-pancakeite here, but if I were faced with this problem I would start haunting craigslist, ebay, and the local pawnshops for a Core-2 desktop box. That 460 will run on the crappy stock PSU's and they would likely have more better and more faster rams than your current box.

It seems self-defeating to start upgrading the processor/ram/mb on an old box when for less than that you can find someone's old machine and put it to good use.

If you live near a largish city you can also look for those computer resellers who buy corporate boxes, wipe the drives and resell them with a warranty for only a bit more. (I am absolutely neither recommending nor not recommending this company that buys my companies used PC's: [URL="http://www.epcusa.com"]www.epcusa.com[/URL] )

If your pc would support a 45nm quad then I saw one on ebay at £35 a day or 2 ago. It is likely though that even if your motherboard supports a quadcore it would only be a 65nm. Still my Q6600 isn't to shabby. It might be time for a pc upgrade though. An ivy bridge 3.6Ghz dual core i3 would likely be faster on a lot of applications than a Q6600.