Left 4 Dead 2
We tested Left 4 Dead 2 by playing back a custom demo using the game's timedemo function. Again, we had all of the image quality options cranked, and we tested with 16X anisotropic filtering and 4X antialiasing. The game's multi-core rendering option was, of course, enabled.
The 1090T consistently trails the X4 965 by a small amount. That suggests the 1090T is generally operating at its 3.2GHz base clock speed in this game, 200MHz shy of the X4 965's speed. Why is that? For a clue, we can turn to the lower-end AMD processors. Note that the Athlon II X4 635, with four cores at 2.9GHz, outperforms the Phenom II X2 550, with two cores at 3.1GHz (and more cache). That suggests Left 4 Dead 2 is making good use of multithreading, and the presence of four robust threads may be keeping the Phenom II X6 chips from ranging into their Turbo Core frequencies.
In fact, the X6 1090T has yet to best the X4 965 in any of our gaming tests. That's not a major upset, because newer games running in Windows 7 do seem to take advantage of threading pretty well. We'll have to keep an eye on this question in other lightly multithreaded benchmarks as we go.
Source engine particle simulation
Next up is a test we picked up during a visit to Valve Software, the developers of the Half-Life games. They had been working to incorporate support for multi-core processors into their Source game engine, and they cooked up some benchmarks to demonstrate the benefits of multithreading.
This test runs a particle simulation inside of the Source engine. Most games today use particle systems to create effects like smoke, steam, and fire, but the realism and interactivity of those effects are limited by the available computing horsepower. Valve's particle system distributes the load across multiple CPU cores.
Our CPUs are finally put to good use by Valve's particle simulation test, which shows a clear progression from our cheaper, slower test subjects to their quicker siblings. The Phenom II X6 1055T finds itself almost neck-and-neck with the Core i5-750, its intended target, while the 1090T doesn't quite manage to catch up to the i7-870 and i7-930.