In the days of Intel Pentium, Intel Pentium II and AMD K6 processors, a processor had only a single set of bus lines that communicated with the rest of the system called the frontside bus (FSB).FSB speeds went from 66MHz to 100MHz and then to 133MHz, but, even so, the speed of memory access was a significant bottleneck that restricted performance. Intel invested heavily in the very expensive Rambus memory that was much faster than the current standard SDRAM memory. Intel signed an agreement that prevented AMD from using the Rambus technology.AMD (Intel's only competitor in the PC processor market) developed an alternative called double data rate (DDR) memory, which transfers two bits of data per clock signal instead of just one (hence the double data rate).This matched Rambus memory and was considerably cheaper.Intel has itself now adopted DDR/DDR2/DDR3 memory AMD integrated the memory controller on the motherboard into the central processor chip, which enables a processor to have a separate memory bus that runs at a much higher speed.
Therefore,AMD Athlon processors have separate bus lines running at different speeds for the memory and the motherboard chipset access. The DDR memory bus clock speed (the FSB) is set to half the speed of the memory, For example, with 400MHz-rated DDR memory the FSB would run at 200MHz. The FSB that connects the processor to the motherboard chipset originally ran at
100MHz, then 133MHz, then 166MHz, and finally at 200MHz. In your computer, it should be running at 166MHz, but you have it set at 133MHz. That is why it the processor is configured and reported as an Athlon XP 2200+ processor instead of what it is - a AMD Athlon XP 2800+.
Your computer seems to have the first Thoroughbred chip. Most motherboards detect the correct settings for the processor automatically. This can be completely automatic, as it is with most Dell, HP and other major brands, or there may be a BIOS option that loads default values. The BIOS setup program can offer two sets of default values - failsafe (slow but reliable) and optimal (best). However, the BIOS setup program itself and the motherboard's user manual don't make it clear which is which. The latest processor of a range (Athlon XP 3200+ using an FSB of
200MHz was the last in the line) might be too recent for the original motherboard BIOS to be able to recognise it automatically. However, the computer manufacturer or the motherboard manufacturer usually provide a BIOS update that enables the BIOS to recognise the latest processors in a range. If an update is available from either of the sites of those manufacturers, you should install it (reflash the BIOS with it). The update itself should provide a readme file that provides instructions on how to reflash the BIOS.
