Intel Got Centrino Right!I have found that most people do not understand how the Pentium M or “Centrino” processors work. I will do my best to explain the difference between the new mobile processors verses the full blown versions like the Pentium 4. Ok…for those who know better, the processor is actually the Pentium M and Centrino is the combination of a Pentium M, Intel 855PM or 855GM chipsets, and Intel PRO/Wireless 2100 (or future versions).
Speed: 1.6 GHz = 2.5 GHz?
This is probably one of the most confusing aspects for the average consumer. Centrino chips benchmark much faster than their GHz rating. How is this possible? It is important to know that Intel completely redesigned the Centrino chips from scratch creating a new architecture that is completely new and different. The Pentium M has a better stack manager, branch prediction is more efficient, increased amount of level 2 cache (1 Mb or 2 Mb), more Level 1 cache (four times more data cache than the Pentium 4 class of processors), and the pipeline isn’t as deep in order to avoid the penalty for faulty branch predictions. Also, the Pentium M accepts SSE2 instructions like the Pentium 4.
Lower Power Consumption
The Pentium M uses third-generation SpeedStep technology to raise and lower the clock speeds and core voltages. This technology allows the processor to use more power when needed and less when it isn’t. Power conservation is nearly as important as power in a mobile processor because lower power consumption means a longer battery life. What good is a fast processor if your batter only lasts one hour? Not to say that the Pentium M isn’t a fast processor.
But How Good is the Chipset?
Intel designed the Pentium M to work with the 855 core-logic chipset, which has a 400MHz front-side bus, support for DDR333 memory, and a few power saving features. The 855 chipset can send power-down instructions to the Pentium M and is also capable of shutting down elements of the system bus to further conserve power which goes hand in hand with the SpeedStep technology. A series of ultra-deep sleep states rounds out the 855 chipset's power-saving features. Some versions of this chipset only allow for integrated graphics and others include an AGP 4x slot. Overall, the chipset is good and conserves power well.