SLI Performance And Scaling
Here’s where things start heating up. The above chart shows the performance of Nvidia’s GeForce GTX 480 in single-, dual-, and triple-card configurations at 2560x1600 in our six benchmarked games with 4xAA turned on.
Those results translate into the above scaling numbers (Metro 2033 is off the chart because the baseline is so low; for the same reason, its greater-than-200% scaling number in SLI is also insignificant).
At the very worst, SLI is good for a 71% performance increase (in Just Cause 2). At the very best, it yields 89% additional performance (in S.T.A.L.K.E.R.). Three other games fall between in an impressively-close spread. It turns out that two-card SLI is a very effective way to improve the performance of a gaming machine.
In all six titles, 3-way SLI works, but it’s hardly as effective. There’s more speed to be had from a third GeForce GTX 480; I don’t necessarily think the boost justifies tripling cost, though.