A common question for those looking to buy an xbox 360 is one of how to identify what chipset a particular xbox 360 has.
The main reason for this is reliability. Newer version of the 360 are known to have better reliability and less chance of the dreaded, well documented red ring of death (RROD for short). This is where the xbox produces an error often from overheating which causes the console to lock up and stop working. Microsoft had to admit the fault and up to a point will provide a replacement console free of charge for those under warrenty.
The easiest was to avoid the RROD is to look at the chipset of the console.
The Jasper chipset is the name of the CPU/GPU chipset in the new versions of the 360. You can identify which chipset you have by looking at the label next to the power socket. On the label it says 12V DC followed by a current rating.
The 2nd generation had a current rating of 14.2A, the Opus/Falcon chipset.
The latest generation has a rating of 12.1A this is the Jasper chipset.
The newer chipsets do not draw as much power and therefore are less prone to overheating, so where possibly always opt for a Jasper version.