Breaking down the Xbox 360

Two versions of the Xbox 360 will go on sale Tuesday in stores: a $300 "core" system and a $400 one with some extra gear. Here's what you'll get for your money:

Speed and memory

Inside the box are three processors that each run at 3.2 gigahertz and a graphics processor that can go as fast as 500 megahertz. Microsoft says the machine will offer four times the number of pixels per second than the original Xbox — but that won't be as big a deal on regular televisions as it would be on high-definition screens. The machine has 512 megabytes of memory — eight times that of the original Xbox. There are also two fans and a cooling system to keep the console from overheating.

Hard drive

The 20-gigabyte hard drive is detachable and can fit into your pocket. It isn't necessary to play games, but it can store game features and thousands of songs from compact discs. It doesn't come with the Xbox 360 Core System, and sells separately for $100.

DVD capable

Will play games, DVDs, compact discs and DVD-ROMs.

Three USB ports

Two in front and one in back. You can plug an iPod or other MP3 player in and stream music to the system while you're playing games, but there's a catch: Due to incompatibility issues, the machine won't play songs purchased from Apple's iTunes Music Store. You can also plug in a digital camera and view photos.

Wired and wireless controllers

The Xbox 360 can handle up to four wireless controllers, although the Core System only comes with a wired one. There are only two ports on the front of the machine for wired controllers. Headsets used for talking to others on the Xbox Live system can be plugged directly into the controllers.

High-definition gaming

Microsoft has required that all Xbox 360 games have an option for high-definition resolutions (up to 720 progressive scan and 1080 interlace, if you pay attention to those things). The games will work on standard televisions as well. But if you want to play high-definition games on your high-definition television, you'll need a special cable that doesn't come with the Core System.

Removable faceplate

The front plate, including the power button, snaps off and can be replaced with different colored versions. Microsoft is only selling a few versions so far for $20, including silver, blue and wood-grain editions.

Memory units

Two slots for memory units, which for now only come in one size: 64 MB. These $40 memory units aren't necessary if you have a hard drive, but they are handy for transporting data, such as your gamer profile or a few songs, for use in other Xboxes.