Quad SLI system cannot really boast much here: it yields to GeForce 7900 GTX SLI as well as to Radeon X1900 XT CrossFire.
In FSAA 8x mode it finally manages to outperform its dual-GPU counterpart – GeForce 7900 GTX SLI. However Radeon X1900 XT CrossFire remains undefeated. The leader is not too far ahead, the gap is only 6%-8% in 1600x1200, but the fact is undeniable: in equal testing conditions GeForce 7900 quad SLI platform is slower than the dual-GPU CrossFire.
Radeon X1900 XT CrossFire supports Super AA 14x and hence works in slightly lighter conditions, however it has tremendous performance advantage over the GeForce 7900 quad SLI. At the same time, GeForce 7900 quad SLI gets quite far ahead of the GeForce 7900 GTX SLI: in 1600x1200 the advantage is close to 70%.
Since half-Life 2 is not one of the resource demanding games, we managed to get our Quad SLI system perform at an acceptable level in SLI AA 32x, although only in 1280x1024. So far this is the only game where this mode can actually be playable.