SLI Question

[scratchyrice]

Basicly, I currently have an 8800GTS640 (g80). I've been looking on e bay, And i can get a second one for about £30 nowadays.
1. Is it worth it? According to toms hardware i will see about a 30 - 45% increase in performance in gaming. However, my trustworthyness in them was broken when i also saw that Oblivion runs at 58fps on the g80 320MB, but only at 53fps on the g80 640MB. Personally i think that must be untrue, As they are both exactly the same cards in terms of clock etc, Except one has more memory. So if anything mine should be faster
2. I purchased the BFG OC'ed version of the card (to 550MHZ core instead of 500). Will i now have to get the exact same OC'ed version of the card for it to work? Or does it only have to be the same chipset and manufacture (BFG + G80)?

As currently all games apart from crysis (of course) will run on highest settings at 1280x1024 x4 antialiasing - Which is good enough for me. However, A new gpu would bring more advantages in development terms. The current game in working on will rely heavily on the Physx engine (If physics setting turned on high), And i need a system to test it on. With an extra card, I could set it to be a dedicated physx card. Also does the ogre render support sli?

Cheers

Scratchy

[Penguin]

Generally, it's always better to go with a single faster card, then to get two slower cards. There is some inefficiency with SLI.

[scratchyrice]

Indeed, however i do not have the cash for one 280, 9800X2 or 295. Adding a cheap extra card, is probably more bang for buck, is it not? Is this not the idea of sli? Adding an extra cheap card when one no longer pulls the weight?

Cheers

Scratchy

[jjp]

If your mainboard supports SLI, your power supply does have the head room for another card and your cooling system can deal with the additional heat: why not. But don't just look at the framerates when deciding, there is one catch with multi GPU: http://www.pcgameshardware.de/aid,63166 ... arte/Test/

The purpose of multi GPU is mostly surpass the performance of the most powerful single GPU card. As already said, there are a few downsides:

- more expensive mainboard,
- more expensive power supply,
- more demanding for the cooling system,
- more noise than a single card of comparable speed (usually),
- micro-stuttering,
- no doubled performance due to overhead,
- dependent on driver support.