CPU Binning

I have been wondering for some time now how it is actually done. How does AMD or Intel get from the wafer to the point where the cpus are ready to be sold.

How do they tell how well the chip will perform. The lower VIDs for the server parts. Higher quality parts for the top of the line verision(extreme editions FX's). The clock/multi they are going to running at.

The newly fabbed CPU is connected to a special "tester" machine (see: teradyne.com for one vendor). This machine controls all of the pins to the CPU, and specially-written test programs are played onto the pins (with expected results). The clock and voltage are increased until the point of failure, and this determines which bin it makes.

Disclaimer: I work for Intel, and I am greatly simplifying things, but this is the basic explanation.

Thank you Phanboy. I figured they had to hook it to some kind of machine to test out what the cpu can do. But coudnt think of a way of doing without putting it in a actual PC. I suppose something close to this same process is done for ram. To determin its frequency/timings/voltage.

Deathwalking you could arque that every single intel conroe based cpu is underbinned. Even the top of the lines. I have never come across or read about a conroe that couldnt be pushed up a couple 100mhz with stock volts. But if Intel was losing the cpu power race with AMD, best believe they would crank up the clock speeds on the conroe/penryn(cores)