MTE Check Disc
The MTE Retail Check Disc is a disc designed to stress an XBOX 360 out to the point it overheats, It contains an early version of Project Gotham 3 and many other tests.
Below are pictures from an MTE Retail Check Disc, There's also a version named Ping17 which is pretty much the same minus the default.xex remains unlike this which was removed and placed on a USB Dongle.
Ping17 also doesn't contain the pictures seen below.
There's a version for the XBOX ONE, the few people who have say the disc is blank but this is unconfirmed.