Pentium & Cache

Pentium III Xeon (processor) with 2 MB on die-cache has 140 million transistors. Cache memory stores the frequently accessed data. Cache memory on motherboard are called L2 (level 2) Cache while that on processor is called L1 Cache - more faster than L2. Later 486 chips has on die-cache (L1 cache) and L2 cache runs at motherboard speed. Now a days L1 and L2 cache are running at processor speed. We cannot compare systems on pure MHz done because other factors affect system performance (efficiency).

Pentium 4 runs at 2.1 GHz while the motherboard speed is 400 MHz (5.25 x). The processors used today can run at different speeds depending on motherboard speeds. 2.93 GHz (Pentium IV) is the maximum speed in which we can run the processor depending on motherboard and other parameters (32/64 data bus) etc.