After questions from many readers, we will recall some details on the processors equipping our new portables. Here are the principle new features: - fabricated in 45 nm process: this along with other optimizations allows the reduction of power used by the processor. Note that Apple has revued its method for calculating the time to discharge the battery; this gives the impression that the new portables have a shorter time on battery power - however the numbers now are really just more realistic. The old figures were never really attainable except by switching off wifi and turning down the brightness of the display... ie doing nothing with the computer. - Increase of L2 cache that is now 3 MB (compared to 2 MB previously) on the base model MBP and the MacBooks, and 6 MB (compared to 4 MB) on the high range MBP: this increased cache will improve the performance in certain conditions. - Addition of SSE4. This new instruction set is expected to have a big performance enhancement for multimedia applications. However currently this enhancement is not seen. It will be necessary to recompile the programs with new specially written code to take full advantage of the SSE4 instruction set. - an overdrive function that allows the processor to automatically overclock in certain cases. For this, it is strongly suggested that one run monothreaded applications. In this case, one core is disactivated while the other runs at a higher frequency. Tests have shown that this can be done only for short periods of time, the system will disactivate this feature quickly due to risk of overheating the core. Here is the list of Penryn used by Apple: T8100: 2,1 GHz 3 MB of cache with 800 MHz bus (MacBook entry level) T8300: 2,4 GHz 3 MB of cache with 800 MHz bus (MacBook et Macbook pro entry level) T9300: 2,5 GHz 6 MB of cachewith 800 MHz bus (MacBook Pro) T9500: 2,6 GHz 6 MB of cache with 800 MHz bus (MacBook Pro BTO) [translation by crispin]

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	www.hardmac.com/news/2008-02-28/#7865