mmic29 schrieb:
3. dürfen unterschiedl. getaktet sein; die höher getaktete passt sich dann automat. der niedriger getakteten an
http://forums.slizone.com/index.php?showtopic=4776
General SLI Inquiries
Q: Can I use two different video cards in SLI?
A: Not unless the cards meet the requirements for SLI: both cards must be of the same family and model, but nearly everything else can either be compensated for (such as clock speeds) or does not have to be similar (VGA BIOS versions, manufacturers, etc.) For example, an 8600 GTS and a 7600 GT couldn't be used in SLI because they differ on both levels. If you have a card, say an EVGA 7900 GS, that you bought some time ago but want to combine with an ASUS 7900 GS you just bought, then there shouldn't be any problem.
Q: Can I have two cards with different speeds/memory amounts in SLI?
A: Of course! It'll just take a little extra work. When there is a discrepancy between two graphics cards' specifications (for example, GPU clock) you have one of two options: install the slower card in the primary PCI-Express slot or install the faster card in the primary slot. Setting the slower card as the master automatically underclocks and adjusts the speeds of the faster card to match that of the less fortunate card, which keeps them in step. When you set the faster card as the master, the slower card gets its speeds beefed up to that of the master card. Doing this can cause system instability, visual artifacts, higher GPU temperatures and sometimes component failure, so only do this when the cards can handle it (third-party cooling, excellent air circulation and only moderate differences between the speeds.) The same goes for memory speeds, not just GPU speeds, in case there were any questions. Now, this is not the same when the memory sizes of the two cards differ, such as the 8800 GTSs or the 7800 GTXs. When one card has more VRAM than the other, the card with less memory has to be installed in the primary PCI-Express slot to run SLI. Additionally, you will need to change the CoolBits registry string and change its value to 18. This automatically disables a certain amount of memory banks on the other card, making all things equal between them. This can't work in the other way because, well, you can't just magically create memory banks, as nice as that would be.
1. Also kommt es auf die "Masterkarte" im ersten Slot an welche Takte gefahren werden.