7900 GTX OC SLIed with 7900 GTO? (can they be paired?)

vpsaline

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Does anyone have first hand experience SLI-ing these two cards together or knows of an internet article where it is done? Does anyone know if it can be done and with significant performance boosts?

7900 GTX OC
GPU: G71
Pixel Shaders: 24
Vertex Pipes: 8
ROPs: 16
Memory Size: 512
Memory Type: GDR3
Core Clock: 670MHz
Memory Clock: 1640MHz

3D_Mark_06: 6750pts /SLI 11,000pts

7900 GTO
GPU: G71
Pixel Shaders: 24
Vertex Pipes: 8
ROPs: 16
Memory Size: 512
Memory Type: GDR3
Core Clock: 650MHz
Memory Clock: 1320MHz

3D_Mark_06: 6,100pts /SLI 10,250pts
 

lambofgode3x

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well, a gto is basically a gtx. the gto is actually made from left over gtx parts. if you can get your hands on the 7900gtx bios and flash the gto card, you should theoretically be able to do it.

wait to see what others say. you might be able to do it without flashing the gto, but i doubt it's possible without flashing.
 

darkstar782

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Yes it can, but the GTX will slow down on speed to keep level with the GTO :wink:

Ok that is exactly what I was thinking, but how sure are you, cause im not 100%, are you 100% sure?

It will NOT work out of the box.

The nVidia drivers simply wont allow it to work.

DO NOT flash the GTO with a GTX BIOS.

This will NOT work as the GTO RAM will NOT work at 1600MHz.

The best thing you can do, is use nBiToR to read the BIOS from your 7900GTO, change the device to 7900GTX, WHILE LEAVING THE RAM TIMINGS AND FREQUENCIES THE SAME.

Save this modded Bios and flash it with nvflash. You will need to use the -5 and -6 switches to override the device id mismatch.

the command would therefore be:

nvflash -5 -6 newbios.rom

You then have a 7900GTX, and a 7900GTX with slow RAM. They will then work in SLI, the faster card will slow its RAM down to match the slower card.

nBiToR and nvflash can be found over at MVKtech

This process will allow any 24 pipe G71 card to work with any other. This includes 7900GT, 7900GTX, 7900GTO, and 7950GT. The cards will operate at the speed and framebuffer size of the slowest card / card with least RAM
 

vpsaline

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wow very informative, thank you. If anything else comes to mind, anything at all, please add to it :lol:

Do you think being the owner of a 7900 GTX OC and buying a GTO to SLI is a wise move?
 

vpsaline

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Well, my GTO RAM works at 1600mhz.

Well from what Ive learned is that GTO easily reaches 1600mhz because it does not have the GTX's "tighter memory timings". The GTO bios has relaxed timings so reaching 1600mhz shouldnt be too much of a problem but it is not equivalent speed to a GTX bios @1600mhz.

Why don't you just get a GTX? I've found them to be cheaper now than getting a GTO. The GTOs are hard to get hold of.

Well here in canada, GTOs= 280$<>310$ & GTX=410$<>560$
 

darkstar782

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wow very informative, thank you. If anything else comes to mind, anything at all, please add to it :lol:

Do you think being the owner of a 7900 GTX OC and buying a GTO to SLI is a wise move?

The 7900GTO isnt a bad card, and the RAM will likely have some juice left in it. You'll get a reasonable performance boost.

Flashing straight to the 7900GTX BIOS isnt a good idea though because even if your card will overclock to 1600MHz, it doesnt take into account the RAM timings as you have said.

However, even 7900GTX SLI isnt as fast as a single 8800GTX. You are spending alot of money for a DX9.0c setup....

I know the 8800GTX doesnt come cheap, but dont forget that in buying one of them you could sell your 7900GTX on eBay or similar.