Is two graphic cards better than one without sli

[demonicfish]

Hi this will probley sound pretty noob to most of you but i have a geforce 9800gtx/9800gtx and a geforce 8800 both cards are sli cable but there not the same card so i cant use sli, I have both cards in my pc now an everything runs fine i play call of duty black ops online in high settings an everything runs great my question is when im using my geforce 9800gtx is the 8800 doing anything at all or i should i just remove it an put it in my old pc, on a side note the 9800gtx is the card i bought to replace one of my geforce 8800 cards that broke my question is does 2 geforce 8800 cards running with sli run faster than my current set up i really cant tell the difrence but i could aways get my old broken 8800 card replaced if those cards working togeather would work better,
And lastly ive heard even if my 2 graphic cards dont use sli i can make one do the physx processing in games an i get that option in my nvidia control pannel but which should i set to use physx or should i just leave it on auto select, sorry if my english isnt so great but its not my first langauge, any help you can give would be aprecated thanks.

[Rik_]

SLI is for high resolutions, not speed. At a resolution like 1024x768 the second card will do absolutely nothing at all!

[zash20]

wow i did not know that thanks rik.

[Rik_]

No problem! A friend of mine found that out the expensive way!

[saxmaster49]

you can sli the 9800 and 8800 if you want, its called hybrid sli. You can do this with any nvidia cards that are 8800's or newer. The only drawback to this is that if one card has less memory than the other both cards will use the lesser amount of memory.

I would use the 8800 for physx and the 9800 for graphics, you will notice a significant increase in fps for physx games. CUDA for nvidia cards running on a single card causes the card to run only at around 80% efficiency.