Monday, August 21, 2006

Low Power and Energy-Efficient CPUs from Intel and AMD


Review by MS, August 20, 2006)
http://www.lostcircuits.com/cpu/low_e/14.shtml
Final Words
Since its launch - or even earlier than that - the Core2 Duo processors have been hailed to be the non-surplussed leaders in CPU performance. As the claim to fame usually goes, the glory rubs off on every single member of the family, so that by the end of the day it really doesn't matter whether it is an E6700 or an X6800 or maybe just an E6300. All of them deliver spectacular performance not only with respect to the instructions per clock cycle but also in terms of instructions per Watt. At least that's the storyline.
At the same time, AMD is back to some sort of wall flower existence, since only being Number One is what attracts the spotlights. However,the reality is a bit more convoluted; starting with the Venice core, AMD has delivered outstanding performance per Watt. With the introduction of the Dual Core Athlon 64's, the focus has shifted once again towards performance rather than efficiency but there was no doubt that at least the potential for the next big thing in power savings was there. Along with that necessarily goes the issue of thermal management of CPUs.
One thing that is quite amazing about the Core2 Duo / Extreme is its performance scaling with clock speed. The higher the clock is pushed, the better it'll perform. Keep in mind, though that every coin does have two sides, in other words, what goes around, comes around and by extension, that means a significant performance gap between the lower and the higher speed grades. Compared to the P4, this still positions even the Core2 Duo E6300 as Intel's sexiest silicon since implants but on the other hand, some claims about even the lowest Core2 Duo outperforming the fastest AMD processors more or less belong into the realm of urban legends.
When it comes to performance per W, one thing is absolute sure, the "ADD" series sets completely new standards. Granted that the overall performance is lower than that of AMD's high end CPUs but there is still enough horsepower for about anything and in terms of energy-efficiency they are nothing short of breathtaking.
Pricing is currently in a complete turmoil with both AMD and Intel chasing each other's tail and it is almost impossible to factor it in other than for a snapshot but at least at the low end, anything other than approximate price parity would be difficult to argue. By the end of the day, the E6300 was a bit of a disappointment, primarily in comparison to the higher speed grades' performance and also based on the power consumption but we still have to give it the benefit of the doubt for the simple reason that what we have is a preproduction sample and that the "real" thing may be more energy-efficient.
The "ADD" X2-3800+ does not get any benefit of the doubt when it comes to energy-efficiency, but fankly, it doesn't need any of this anyway. As it stands, both energy-efficient processor lines are setting new standards but despite its nominally lower performance, the "ADD" X2-3800+ is the better processor in the bunch.

No comments: