Presler Processor Details
All the upcoming Intel chips, including the Pentium 4 600 series and the Pentium D 800 and 900 series, feature the 64 bit extensions feature called EM64T, the execute disable (xD) bit for virus defense (using Windows XP Service Pack 2) and Enhanced Intel SpeedStep (EIST), which reduces voltage and clock speed at low loads (and needs BIOS support). All Pentium D 900 processors will come with VT enabled. Unlike the 800 series Pentium D, the 900 series Preslers will allow for clock speeds of up to 3.4 GHz at launch (the Pentium D 950).
What we expected in terms of performance came true. Thanks to the L2 cache being doubled from 2x 1 MB to 2x 2 MB with the Cedar Mill core, certain benchmarks improve on the new chip when compared to the Smithfield at the same clock speed - our sample ran 3.0 GHz.
Once again we included some power consumption measurements. While the single core saved as much as 20% under full load, the dual core Presler managed to reduce overall consumption by as much as 18%, cutting maximum system power from 252 to 214 W.
The power savings we were able to achieve with SpeedStep enabled were rather disappointing. However, we should not forget that in the case of the CPU sample we borrowed, the clock speed would only go from 3.0 to 2.8 GHz. On the other hand there is the larger pair of caches that should be taken into account. Although the number of transistors increased by at least a third, the power consumption level still is below Smithfield in most cases. And we expect the final processor version to be somewhat better optimized.