Wednesday, April 1, 2009
Pentium III Xeon family was manufactured using two different cores:
0.25 micron Xeon processors are based on Tanner core, which is very close to Pentium III Katmai core. The main difference between Tanner Xeons and Katmai Pentiums lies in the size and operating frequency of level 2 cache: the Xeon CPUs have much larger, up to 2 MB, L2 cache running at CPU frequency, that is twice as fast as Katmai L2 cache.
Next generation of Xeon processors was produced using 0.18 micro technology. There were two different versions of these processors - with 100 and 133 MHz Front Side Bus frequency. All Xeon microprocessors with 133 MHz FSB were in effect Pentium III Coppermine processors in Xeon package. Like desktop Pentium III CPUs, they had 256 KB level 2 cache integrated on the processor core and didn't support quad-processing. Performance of these Xeons was no better than performance of desktop processors. Later Intel released real Xeon processors that could work in 4-way systems and had very large, up to 2 MB, L2 cache. The disadvantage of these processors was lower FSB - only 100 MHz.
All Pentium 3 Xeon CPUs were packaged in the same bulky and heavy 330-contact SECC cartridge as Pentium II Xeons.