To keep things on an even keel, we chose a quad-core CPU for our test bed--an overclocked Intel Core 2 Quad Q6600 at 2.7 GHz. After we ran all of our benchmarks on the system, we then disabled one of the cores, rebooted, and ran the benchmarks again. We rinsed and repeated until we had results for one to four CPU cores, all running at identical clock speeds on the same CPU.

It turns out that disabling a CPU core in Windows is easy to do. If you’re interested in trying it yourself, simply type "msconfig" in Windows Vista's "Start Search" field and hit enter. This will open up the system-configuration application.

From here, click the "Boot" tab, and then click the "Advanced options" button.

This will bring up the "BOOT Advanced Options" pop-up menu. Simply click the "Number of Processors" check-box and select the number of processors you’d like your system to use from the drop-down menu. It’s that simple.

After clicking "okay," you’ll be prompted to reboot. After the reboot, you can easily see if the proper number of processor cores is available through Windows Task Manager. Open the task manager by simultaneously hitting "Ctrl-Alt-Delete’" and selecting "Task Manager" from the pop-up menu.

Then, select the "Performance" tab. You will see a CPU-usage graph for each enabled processor (whether it's physical, as seen here, or logical, as you'd get from a Core i7 with Hyper-Threading) under "CPU Usage History." Two histograms mean that two cores are enabled, three mean three cores are active, etc.

Now that you know the method to our madness, let’s go over the details of the hardware and software we use for our tests.