X-bit labs

Intel Pentium M 780 as Heart of Your Desktop PC, with ASUS CT-479 Adapter (page 9)

Category: CPU

by Ilya Gavrichenkov

[ 06/20/2005 | 01:46 PM ]

Power Consumption

Pentium M processors were specifically developed for mobile computers, and low heat dissipation and power consumption were among the design priorities. For example, the maximum thermal design power of the Pentium M 780 is four times lower than that of the Pentium 4 670. But we are more interested in knowing the typical consumption of processors in real-life uses. So we measured the current consumed by the processor (which was running S&M 1.6.0) with the help of a clamp-on ammeter. The results are listed below. The numbers we got do not count in the efficiency of the mainboard’s voltage converter.

As you see, the Pentium M boasts a very low power consumption under high load. It is six times lower than that of senior Pentium 4 models but is also two times lower than that of the Athlon 64 on the new Venice core. It is no wonder then that the Pentium M 780 can get along with a small aluminum cooler while coolers for desktop processors have long had copper inserts at the least.

Now let’s see what power consumption the Pentium M has in the idle mode. Note that we disabled Enhanced Intel SpeedStep technology for the time of our tests for all the processors, but Pentium 4 CPUs drop their frequency to 2.8GHz when idle by means of Enhanced Halt State technology which doesn’t have an analog in the Pentium M.

The Pentium M is not an unrivalled leader here. The new processors of the Athlon 64 family on the Venice core can boast about a similarly low power consumption in the idle mode. But if we compare the idle power consumption of the Pentium M with that of the Pentium 4, we can see that the mobile processor still has a considerable advantage, even though it cannot use its special power-saving technologies when combined with an ASUS CT-479 adapter.

So, the Pentium M can make an excellent foundation for an economical computer. This CPU consumes little power and heats up very little under load. Thus, it suits ideally for home systems.