Once again, the 6600 GT is unplayable. What’s interesting is that the UT3 engine seems to favor the Radeon 2600 XT’s universal shader power over the X1950 PRO’s superior memory bandwidth. If the performance bump was attributable to the 2600 XT’s PCIe interface, the difference between the AGP 3850 and the underclocked PCIe 3870 would have been noticeable.

We’re also seeing a continuation of the same theme: while the 3800 series cards get the highest frame rates of the bunch, the average is still abut 20 frames per second, not the 30 minimum we’d need for smooth gameplay.

Supreme Commander is known to be a heavily multithreaded game engine, and we can see all of the cards are being bottlenecked by the CPU, even at minimal detail settings. Even the 6600 GT performs almost as well as every other card we benchmarked. Because the game is a real time strategy title, and not a “twitch” game like a first person shooter, it’s playable—but not pretty.

Flight Simulator X is the only game that suggests any possible evidence of the AGP 8x interface acting as a bottleneck; both the PCIe 2600 XT and underclocked PCIe 3870 show a slight but consistent lead over the other cards. However, there’s clearly a CPU bottleneck in this title as well, and the game is barely playable at the maximum settings.