Tuesday, November 13, 2007

Processor


Intel takes the wraps off the latest version of the Pentium M, previously codenamed Dothan. This new design moves the Pentium M to 90-nanometer manufacturing process, pushes up clock rates, and doubles the L2 cache. While none of the changes in Dothan can be called revolutionary, it appears that Intel has improved key areas of the original Banias design from lessons learned in the field.
What is L2 Cache? (Level 2 Cache) - A piece of fast memory that sits between the L1 cache of the processor and main memory. It is usually larger than L1 cache, and the L1 cache checks the L2 cache before going to main memory for data (unless the L1 and L2 caches are unified--see unified cache). Nowadays L2 caches are almost always on the same die as the processor, but they can be off-chip. An on-die L2 cache is a faster alternative to an SRAM cache, particularly as CPU clock speeds continue to increase.The most important entries here are the changes in the L1 and L2 cache sizes, where the L1 is 4X bigger and the L2 doubles in size. In fact, the doubling of the L2 cache probably accounts for much of the 81% increase in transistor count. Dothan also offers about an 18% higher peak clock rate, as well as a lower thermal envelope, thanks to the move to Intel's 90-nanometer manufacturing process.The biggest new feature in Dothan is the big L2 cache, which is the same size as that found in Intel's Pentium 4 Extreme Edition.

No comments: