You can customize your build with up to 4 GB (8 GB when you choose a 64-bit O/s) of Corsair DDR2 memory running at 667 or 800 MHz. Because the RAM modules support EPP they can be overclocked to 1067 MHz. You should note that if you opt for the standard RAM modules, EPP is not available. Other than RAM overclocking, Dell limits the overclocking support to only the CPU multiplier as you can't change the front-side bus clock, the memory clock, or voltages.
The chassis of the XPS 720 is large, but stylish. It features Dell's LightFX system of colored LED lights that change in sync with your computing experience getting cues from your video games, multimedia or other software. The chassis features many input options including 10 USB ports (2 internal, 2 front, 2 back). In spite of the large size of the case, it remains fairly cramped because of the large cooling unit, and dual 8800 GPUs.
The XPS 720 H2C is an expensive rig, starting at $5900, but more powerful overclocked setups such as a QX6800 CPU overclocked at 3.46 GHz will cost over $7000.
Dell's XPS line of gaming desktops competes with their Alienware division that includes products like the Alienware Area-51 ALX.