Intel Pentium-M Closer Look
Here's a quick run-down of the Pentium M "Dothan" core processors available at this time. We used a Pentium M 755 for testing with the new DFI 855GME-MGF motherboard.
As you can see, although this is a 478 pin Intel processor socket, the Pentium M pin-out is in fact keyed differently than a standard Pentium 4 socket 478 CPU. And the two sockets are not compatible. The internal architecture of the Dothan core Pentium M processor is held very guarded by Intel. In fact, it is not known how many stages Dothan's pipeline has but it is rumored to be somewhere in the neighborhood of 12. This explains the processor's ability to have significantly better overall throughput clock-for-clock versus the 31 stage pipeline in the Pentium 4 Prescott core.
What we are very much aware of is that this new Pentium M core has 2MB of full speed, on chip L2 cache, the same amount of L3 cache that Intel incorporates on their Pentium 4 Extreme Edition CPUs. Intel has recently come to adopt larger cache sizes for all of their future processor P4 designs as well, due to the obvious performance benefits in gaming and multimedia applications.
Finally, what is truly amazing here is the processor's power consumption profile or "thermal design power" as Intel likes to call it. Thermal design power is the maximum power that the processor's thermal solution (in this case the HSF on the CPU and surrounding ventilation in a chassis) is required to dissipate without exceeding the processors maximum junction temperature, in this case 100oC. By stark contrast a Pentium 4 Extreme Edition 3.46GHz CPU, which dissipates over 110 watts TDP (thermal design power), and can only reach a maximum junction temperature of 66oC. With a TDP of only a mere 21 watts (only 5 watts for the Ultra Low Voltage versions), you can imagine just how small and quiet a Pentium M heatsink and fan combination can be, while still providing more than adequate cooling.