Even if you've been living under a rock in the desert, chances are you've heard of Call of Duty: Modern Warfare 2. The game has sold millions of copies worldwide on the PlayStation 3, Xbox 360, and the PC. Like its predecessor, Call of Duty 4, Modern Warfare 2 runs well and looks spectacular. In fact, the minimum requirements for the game have hardly budged at all, which is not to say that the minimum grants you a remotely enjoyable experience. But those that are a few steps up from the bottom can still have a great experience. In case you're looking to get a better experience, we've gone through all the hardware to see what nets you more frames and eye candy.

We used Fraps and the opening sequence of the Act II mission, Hornet's Nest, to measure frame rates in our tests. Hornet's Nest drops you off in a heavily wooded area somewhere in Rio de Janeiro and has you run up a small path leading to a shanty town full of enemies, rampaging trucks, and the ever-present explosive barrels. The level has a nice mix of the environments you're likely to encounter in the game. We ran each test three times and then averaged the results.
Game Settings
Modern Warfare 2 doesn't have too many settings you need to adjust to get the game to run well. You can leave most of them on, but two in particular will take a chomp out of your computer's performance.
Graphics
We tested Modern Warfare 2 with everything from the now-ancient GeForce 6800 up to AMD's current flagship GPU: the Radeon HD 5970. The game runs well on most video cards, but you're likely to find your biggest gains here if you want to upgrade.
CPU
You could grab an Intel Core i7-960 and be done with it, but you can get away with much less. We went through both quad-core and dual-core CPUs to see how much is enough.
Memory
Modern Warfare 2 needs 1GB of RAM to run, but we already know that that's just the starting point. We checked out what upgrading to 2GB, or even 3GB of RAM, can do for performance.

Systems

We put together a few sample systems to show how the game performed using real-world computers. Our slowest machine and the absolute minimum required to run the game, a 3.2GHz Pentium 4 paired with a GeForce 6800, struggled to churn out a barely playable experience at rock-bottom image-quality settings. Our mid-range system, outfitted with a 2.66GHz Core 2 Duo and a Radeon HD 5770, pumped out a more than playable experience with every setting on and a resolution of 1920x1200. The behemoth system, a Core i7-960 paired with the Radeon HD 5970, literally doubled the performance of our midrange sytem. The behemoth is entirely overkill for Modern Warfare 2.
System Setup:High-End System: Intel i7-960, Intel DX58S0, 3GB DDR3, 750GB Seagate 7200.11 SATA Hard Disk Drive, Windows 7 32-bit. Graphics Card: Radeon HD 5970, beta ATI Catalyst.
Mid-Range System: Intel Core 2 E8600 , 2GB Corsair XMS Memory (1GBx2), 750GB Seagate 7200.11 SATA Hard Disk Drive, Windows 7 32-bit. Graphics Card: Radeon 5770, ATI Catalyst 9.11.
Minimum Requirements System: Intel Pentium 4 3.2GHz, Asus P4C800, 1GB Corsair XMS Memory (512MB x 2), 160GB Seagate 7200.7 SATA Hard Disk Drive, Windows XP Professional SP3. Graphics Card: GeForce 6800 128MB, Nvidia ForceWare 191.07.