Processor Bugs

Processor manufacturers use specialized equipment to test their own processors, but you have to settle for a little less. The best processor-testing device to which you have access is a system that you know
is functional; you then can use the diagnostics available from various utility software companies or your system manufacturer to test the motherboard and processor functions. Companies such as Diagsoft, Symantec, Micro 2000, Trinitech, Data Depot, and others offer specialized diagnostics software that can test the system, including the processor. If you don’t want to purchase this type of software, you can perform a quick-and-dirty processor evaluation by using the diagnostics program supplied with your system.Perhaps the most infamous of these bugs is the floating-point division math bug in the early Pentium processors. This and a few other bugs are discussed in detail later in this chapter. Because the processor is the brain of a system, most systems don’t function with a defective processor. If a system seems to have a dead motherboard, try replacing the processor with one from a functioning motherboard that uses the same CPU chip. You might find that the processor in the original board is the culprit. If the system continues to play dead, however, the problem is elsewhere, most likely in the motherboard, memory, or power supply. I must say that in all my years of troubleshooting and repairing PCs, I have rarely encountered defective processors. A few system problems are built in at the factory, although these bugs or design defects are rare. By learning to recognize these problems, you can avoid unnecessary repairs or replacements. Each processor section describes several known defects in that generation of processors, such as the infamous floating-point error in the Pentium.