The people responsible for website X-Bit Labs (http://www.xbitlabs.com) announced, at the beginning of 2003, that there are falsified Athlon XP processors on the market. That falsification is, actually, a process of changing the CPU identification. Dishonest salespersons remove the identification from the processor and glue another one in its place. For instance, they buy an Athlon XP 2000 and change its identification to Athlon XP 2200, selling it at a higher price.
A modification in the processor is required to make this change possible, That modification is done in the tiny metallic contacts in the body of the processor (the so-called "bridges") and that makes the processor believes that it is, actually, a processor with a higher clock.
Since there are external modifications in the processor, it is relatively easy to know whether an Athlon XP is falsified or not. All you have to do is to examine the bridges of the processor and see if some of them have been soldered using a domestic solder, especially the L11, L12 and L5 bridges (such numbers are written on the body of the processor, next to the tiny metallic contacts).
Figure 1: Places in the processor where you should look for signs of falsification.
Figure 2: Detail of the L12 bridge in a falsified processor. Notice the hand-made solder on the processor body .
Besides, the black area where the identification of the processor is looks worn-out (blurred) on falsified processors. Compare the identifications of an original processor and of a falsified one.
Figure 3: Detail of the original processor.
Figure 4: Detail of the falsified processor.
Those tampered processors operate in overclock, that is, with a clock higher than the originally specified one. Because of that, when we use this type of processor we face freezing and random errors.