Valve Source engine particle simulation
Next up are a couple of tests we picked up during a visit to Valve Software, the developers of the Half-Life games. They've been working to incorporate support for multi-core processors into their Source game engine, and they've cooked up a couple of benchmarks to demonstrate the benefits of multithreading.

The first of those tests 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 is limited by the available computing horsepower. Valve's particle system distributes the load across multiple CPU cores.

More CPU-bound applications like Valve's particle simulation benchmark also give the X2 3600+ the top spot in value terms, but they nonetheless see very significant performance gains from faster chips. The Core 2 Quad Q6600's score is nearly four times that of the X2 3600+, for instance. Still, it's hard to argue with cold numbers: the Q6600's price tag is over seven times that of the 3600+'s, and it sits in the bottom half of our score point/dollar chart, clearly bested by dual-core chips on the value scale despite their significantly lower performance.

Within the dual-core realm, a glance at our value chart and scatter plot suggests the Core 2 Duo E4300, the Athlon 64 X2 5600+, and the Core 2 Duo E6600 are the way to go if you'd like a little extra performance over the Athlon 64 X2 3600+. The X2 4400+ doesn't have bad value proposition, but it's no match for the C2D E4300, as our scatter plot shows.

Valve VRAD map compilation
This next test processes a map from Half-Life 2 using Valve's VRAD lighting tool. Valve uses VRAD to precompute lighting that goes into its games. This isn't a real-time process, and it doesn't reflect the performance one would experience while playing a game. It does, however, show how multiple CPU cores can speed up game development.

This second Valve test mirrors the first one somewhat. There's a drastic gap between dual-core and quad-core solutions on the raw performance scale, but high prices prevent quad-core chips from faring all that well on the value scale. Quad-core offerings are obviously your best bet if money is no object (or if you need to compile maps on a regular basis, as the time savings from faster compiles really do add up), but the rest of us will be more interested in chips like the Athlon 64 X2 3600+, the Core 2 Duo E4300, the Core 2 Duo E6400, and the Core 2 Duo E6600. From best to worst value, those appear to be the best deals in the dual-core segment.