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About CPU cache RAM

The CPU must deliver its data at a very high speed. The regular RAM cannot keep up with that speed. Therefore, a sperial RAM type called cache is used as a buffer - temporary storage. To get top performance from the CPU, the number of outgoing transactions must be minimized. The morę data transmissions, which can be contained inside the CPU, the better the performance. Therefore, the Intel 80486 was equipped with a built in mathematical co-processor, ffoating point unit and 8 KB Ll-cache RAM. These two features help minimize the data flow m and out of the CPU.

Cache RAM becomes especially important in clock doubled CPUs, where internal clock frequency is much higher than extemal. Then the cache RAM enhances the "horsepower" of the CPU, by allowing faster receipt or delivery of data. Beginnmg with 486 processors, ćwo layers of cache are employed. The fastest cache RAM is inside the CPU. It is called LI cache. The next layer is the L2 cache, which are smali SRAM chips on the motherboard. See the illustration below of a traditional Pentium PC: