Question about SLI using cards with differing onboard memory

[sboarder1]

I am currently running a single EVGA 8800GTS 320MB graphics card, with two monitors (22" and 23") hooked up to it. I just got a third monitor (24") that I want to add. Therefore, I plan on going SLi with the setup.

I'm looking at getting a 8800GTS 640MB as the second card. My first question is, can I run an 8800GTS 640MB with the 8800GTS 320MB? Would I get any benefit with getting the 640MB version, or would it only utilize 320MB of it so it matches the current 320MB card.

My second question is, is a 550W power supply (Rosewill) enough to power two 8800GTS cards in SLi? That's the power supply I'm currently using for the single 8800GTS, but I'm not sure if I need to get something with more power for the SLI setup.

 

[Traze]

I would be worried for 2 reasons.

First, you can not run 3 monitors in a SLI config without a TripleHead2Go. SLI disables the 2nd cards video ports.

Second, I'd imagine you might just nuke that PSU, but without exact model, can't say for sure.

 

[Domini]

sli will work and your exactly right, it will only use 320mb of the memory.

traze is also correct that you can run 3 monitors with sli. as of now you cant even do dual monitor with sli, but nvidia is releasing a driver soon that should add that.

the psu im kind of iffy about, some rosewills are good and some are very poor.