[SuperFarStucker]

http://www.xbitlabs.com/articles/vid...-quad-sli.html

Doesn't look very promising for a 2000 US + graphics solution, although it does provide a non trivial advantage in some instances at 2560x1600 over dual card solutions, it is not to the order one would hope. The additional cpu utilization seems to exclude it from 'competitive' benchmarking as well.

Out of most people's price range around here anyways, still interesting that there certainly seems to be a performance wall in parallelizing GPU computations [across cores]. Clearly there is simply tons of driver level optimization to be done as the inconsistent results in the review show but one has to wonder how much effort will be invested into it considering it is a rather unprofitable venture due to the small volume being moved. I guess nVidia did not have the system benchmarked sooner to save face because of these problems. It will certainly be interesting to see how such solutions perform after the software matures, although the slow memory coupled to the cards seems to be a thoroughly moronic idea. Hmm, lets devise a 2000 USD graphics solution and put 1.6 ns memory into it. +1 braindead. If they couldn't engineer a better solution to the thermal issues they should have just canned the project to begin with.



Some choice quotes:

Originally Posted by xbitlabs

[We guess the use of slow memory may harm the GeForce 7900 GX2 in particular and the quad SLI concept at large because it is the memory subsystem performance that’s important in high resolutions and extreme full-screen antialiasing modes. Since the memory of the GeForce 7900 GX2 card works at 600 (1200) MHz, its speed is definitely not high enough to satisfy the growing demand for high memory bandwidth of a system like that. In other words, the performance boost from the four graphics processors may be negated by the slow of each individual graphics processor memory. We’re going to check this supposition in our practical tests soon.[bold added for emphasis]

Originally Posted by xbitlabs

The Chronicles of Riddick performed well and even did not crash, however, SLI AA worked really incorrectly: images doubled, tripled, quadrupled and so on.
...
In the Doom III, Quake 4 and Serious Sam 2 we noticed exactly the same effects as in case of the Chronicles of Riddick: once SLI AA and relatively high resolutions are enabled, we see the aforementioned artifacts with AA, which were probably caused by the fact the frame compositing mechanism did not work as it is supposed to.
...
The Call of Duty 2 game usually froze after changing resolution, which made it nearly impossible to benchmark. At the same time, Battlefield 2 game did not start at all.
...
3DMark05 crashed with SLI AA enabled in higher resolutions, while The Elder Scroll’s: Oblivion game froze when we attempted to take screenshots in 2560x1600 resolution with 32xs SLI AA enabled.
...
The continuous crashes, freezes and problems of the currently shipping Nvidia GeForce quad SLI systems may be associated with early revisions of the hardware, but as the hardware is shipping to customers, any issues with stability are totally unacceptable. [bold added for emphasis]

Originally Posted by xbitlabs

The next FSAA mode – FSAA 16x – is too heavy for Quad SLI, at least if we try to get it to work in 1600x1200. Slow memory prevents the new platform from showing its potential and causes its complete failure in 1920x1200 and 2560x1600. Radeon X1900 XT CrossFire outperforms Quad SLI system by 19% and 28% correspondingly.

We see pretty good results in F.E.A.R.: GeForce 7900 quad SLI manages to outperform GeForce 7900 GTX SLI in FSAA 4x mode already. It gets about 25% faster Radeon X1900 XT CrossFire yields to quad SLI system, but also demonstrates pretty decent results. In some complex scenes, the performance still drops below 25fps though.

...
GeForce 7900 Quad SLI cannot outperform Radeon X1900 XT CrossFire despite the four graphics processors working altogether with FSAA 16x activated.


Quad SLI demonstrated 40fps in 1280x1024, which is a pretty good result for SLI AA 32x mode. However in 1600x1200 the performance of the quad-GPU system is only half as fast. In other words, we do not se any real advantages of the top anti-aliasing mode once again.

[-aDaM^]

pretty sad 4 of these 7900 GX2's HARDLY beat x1900 crossfire, laff

and I'm almost 100% sure Alienware and Falcon Northwest has been offering this in some of there rigs for 2months now.

[Spoudazo]

Whoever falls for this quad-GPU stuff needs to read some books on economics and finances :P

[EvilT]

man cant wait till we c the power consumptions