Quad SLI with 9800 GX2: Pushing a System to its Limit

Sometimes it’s the little quirks in life that sneak up on you and change the way you look at the world. The past couple weeks have done that in testing all this new high end gear. Sure, we’ve had our problems testing bleeding edge stuff before, but in putting all of this from CrossFireX through 9800 GX2 Quad SLI to the test, we’ve gotten ourselves lost in some other dimension of existence. It’s the only explanation really. Like Holmes would have said … whatever remains, however improbable … But I’m getting ahead of myself.

Skulltrail (the D5400XS Intel board we’re using that runs both CrossFire and SLI) rivals Frankenstein’s monster. From the 2x LGA775 sockets, FB-DIMMs, and NVIDIA nForce 100 PCIe chips, it’s not for the feint of heart. We’ve been determined to test on a single platform to compare CrossFire and SLI and trying to work out some kinks has given us a little trouble. AMD and NVIDIA and Intel have all worked with us to try and make things go more smoothly (thanks everyone), but there are still some things that we just can’t explain going on.

After loads of nearly useless testing and many conversations with different people, we set out on a trail of mystical discovery that has unlocked secrets of the universe here-to-fore untold. We’ll get to that in a bit, but first we’ve got to stop and take a look at what we are covering today.

Quad SLI. NVIDIA would like us to tell you it’s the new hotness. Certainly, without even opening a page of this review you should all know that this is the top of the top of the line and nothing is faster right now. But we do need to answer a few key questions about this $1200 setup: how does it scale from two GPUs to four, how does scaling compare to CrossFireX, and what kind of performance and value does this solution actually offer.

Honestly, we also have to acknowledge from our previous review of the 9800 GX2 that a single card is enough to run almost any game at maximum settings … that is, with the glaring exception of Crysis. Can Quad SLI change that? From what we saw in our CrossFireX testing from AMD, we would have thought not. However, NVIDIA has managed to get Crysis to scale across all four GPUs despite the interframe dependencies that make it so difficult. Is it enough to run Crysis at a decent resolution with all the eye candy turned on?

Let’s find out …