Originally posted by: AnnihilatorX
Mind that SLi still need an identical card by the same card manufacturer. Whether you can find a seller selling his old card of same BIOS version, same build is a matter of luck.
That's a common misconception about SLI. You do NOT need identical BIOSs. Yet, you do need the same manufacturer, which does add complexity to the SLI upgrader. I've never really liked SLI as an upgrade path personally, though I suppose if someone got an amazing deal on a used card, it could make sense.
Another misconception about SLI is that the next gen will perform almost 2x as well as the previous gen top-of-the-line SLI. 7800GTX does not beat SLI 6800U/GT in any benchmarks at 16x12 4xAA 8xAF. Here's a quick sample from the benches right here on Anandtech:
BF2
6800U SLI....... 53.3
7800GTX......... 53.4
Doom3
6800U SLI....... 75.4
7800GTX......... 54.2
EQ2
6800U SLI....... 24.8
7800GTX......... 21.5
HL2
6800U SLI....... 118.4
7800GTX......... 119
SC:CT
6800U SLI....... 53.7
7800GTX......... 56.5
Those are 5 graphically-demanding and popular games. I wouldn't give either the GTX or the U SLI the win... except maybe with Doom3, which seems to really love SLI. Otherwise, it's pretty much a wash.
Anyway, calling something a "waste of money" is just a silly argument. What kind of car do you drive? If you spent over $5000, you must have wasted money because you could've just bought a used '95 honda since it will get you from point A to point B, right? What is important to one person may not be to another.
You get my point. Those that spend the extra money for a high-end SLI system want the best performance they can get. Right now, that is SLI. Back in January of this year, you could have purchased SLI 6800U/GT. Right now, 9 months later, the only graphic setup that can beat it at 16x12 4xAA/8xAF is
SLI 7800s. The jury is still out for R520, and nV seems to have cancelled the 7800U. So who knows-- there may not be a single card this year that can end up topping SLI 6800U. R520 will have to be faster than the GTX to be able to do it.