I have the LeadTeck Winfast PX6600 TD 256mb video card in my computer. The computer is an ASUS A8N SLI Deluxe with AMD 64 3000+ and 1G of memory. I am running two 21" monitors on it.
I recently bought the new MS Flight Sim and it would just really bog every thing down. I disconnected one monitor to see if it was the video or the memory. It runs much better with one monitor.
1.) Would a second identical card set up in SLI perform well?
2.) Would I be able to run two monitors with the SLI set up?
3.) Would a single newer card like a 7600 work better than the SLI?
Are those LCD monitors and if so, are you running them at native resolution?
Coz if you are then im not surprised if you are getting bogged down. Your card wont handle 2 21" LCDs at native resolution. On the other hand, if you are using CRTs, then you could just drop the resolution.
Dont bother with SLI with that card its better to buy just a single 7600 and run that. It will perform better than SLIed 6600s and consumes less power (because its only one card)
While you might see a bit of a performance difference and could still run 2 monitors with a second card, a newer game like Flight Sim X would run far better with a single, more powerful card.
The 7600 would be a good choice as long as you get the GT version as it supports sm3 and would be far better than 2 6600s in SLI.
The 6600gt (his is a vanilla) in SLI has virtually no more performance than a single 6600gt (according to the vga charts) because the new games just kill it. Hes FAR better off getting a 7600gt, or even a 7600gs if hes short of cash (which considering he has 2 21" monitors seems unlikely)
EDIT: Buying the 7600gt just because it has sm3.0 is stupid because so does the 6600. Buying the 7600gt because its 2.5-3 times faster is a much better reason.