7950GT clocks

[PP Mguire]

Trying to figure out a problem im having with my cards. Idk if its driver related, PSU related (Ha doubt it), motherboard related (i think this), or just my cards being stupid.

Individualy my cards can clock 700-710/770 with no problems whatsoever. But if i put them in SLI i now have to back the clocks down to 685-770. Any ideas why this is? Im thinking motherboard/chipset myself.

EDIT: My bad, i say i have to back it down because at 700/770 3dmark will freeze. Actualy anything past 685-770 will freeze.

[Miker]

It is SLI, SLI puts more stress on everything, just like 4 sticks of RAM does. So you will need to put it at lower speeds for it to work.

[PP Mguire]

Time for new mobo and AM2 rig :(

[Goliath182]

Those 7950's still must scream in games. Wish i would have had SLI :(, ive had a ton of AMD boards with it but ive never bought two g cards.

[PP Mguire]

They do, i play literaly anything on high.....minus that one damn movie BLAH!! But thats CPU bound anyways im guesing.

[Goliath182]

I treid playing that movie and even my pc lagged. Used about 25% of my total CPU so im pretty sure its CPU bound. Though if i got another program that uses more than one core id probably be fine.

[PP Mguire]

Yea me to. Funny thing is Media Player classic apparently sees both cores becasue it defaults to the second core. But with that move im 100% on my second core the whole time. Idk what it is about that movie.

[Goliath182]

The same thing happens to me when i try to play the new HD Batman trailer in VLC. Lags for a bit, works then lags again.

[PP Mguire]

Yea thats my problem. Cept im not using VLC im using CCC Pack, AC3 Filter, and MPClassic.

Oh well, still any ideas why i cant keep my clocks up?

[Goliath182]

I would say its either card or motherboard related. There is a slight chance that it is a PSU issue but i doubt it.

[PP Mguire]

Not from the test i put it through before, i seriously doubt it. Id be willing to guess chipset.

[Goliath182]

Yea thats what im thinking the culprit is. But its still not that bad of a overclock at least it plays games maxed. Cant complain about that.

[PP Mguire]

Yea but i boast about me having 700/770 clocks when i cant have those in SLI :( I hate that.

[Miker]

Did you miss my post? SLI puts more stress on your GPUs and Mobo, so it will not run at such a high speed.

[PP Mguire]

Except on my friends 590 board they run fine at 700/770. Thats why i came to the conclusion that its just chipset.

[Miker]

Same cards? Or does he have the same setup?

[PP Mguire]

I put my cards in his PC.

[Miker]

Yaa, but also know, you could get the same mobo he has and have it not work, or get your same mobo again and have it work.

[PP Mguire]

Nah, i think its just chipset bound to how much bandwidth i can really pull. Try to remember that SLI on my current board is 8x-8x where as his was 16x-16x.