Half-Life 2
Valve's new masterpiece uses AFR by default with SLI, but Far Cry's SFR mode works well (very well, as you'll see) so I test in both modes. A custom timedemo is used, on one of the prison levels later in the game.Half-Life 2 using default AFR
You actually lose performance with SLI when you're CPU limited in Half-Life 2, in AFR mode. However, as resolution increases so does SLI's performance gain, getting you 44% at 1600x1200. Like Doom3, that's enough to keep the game above the Vsync refresh on my LCD for the very large majority of the time.
Half-Life 2 using Far Cry's SFR mode
The SFR mode for Far Cry is actually a larger performance win than AFR in 66.93 on nForce4 SLI, using Ultras. When you're CPU limited it's not the case, but at 1600x1200 there's an extra 62% over that of a single GPU setup.
Let's see that data as a framerate plot.
Framerate influence
Green is SFR, black is AFR. Lowest framerate is 36% higher with SFR and overall you can see it maintaining higher speeds than with the default AFR mode. A lowest framerate of 67fps, and both tests are run at 1600x1200 with 4AA and 8AF, is higher than a decent Vsync cap at that resolution.
