Original URL: http://www.theregister.co.uk/2005/10/20/intel_pax_bench/

Intel's Paxville: too slow, too hot, too dumb

Opteron killer - back to the drawing board?

By Ashlee Vance

Posted in Servers, 20th October 2005 17:58 GMT

When we nicknamed Intel's new dual-core Xeon processor "Hot Carl," we didn't know how prophetic this would be. A fresh set of benchmarks comparing the Xeon with AMD's dual-core Opteron chip show Intel's product to be a power hungry demon that doesn't perform.

GamePC got its hands on some of the Xeons - code-named "Paxville" - and put the chips through a battery of tests. Most startling is the dual-core Xeon's voracious power consumption. Intel reckons Paxville will need 135W for average software loads and run up to 150W at peak. When plugged into a two-way server, this pull proves troubling.

"There's no doubt about it, Intel's dual-core Xeons are their most power hungry Xeons to date," GamePC writes. "Even when idling, two dual-core Xeons consume nearly 400W of power at any given time, which is amazingly high, even by Intel's standards.

"AMD's competing dual-core Opteron processors consume far less power, especially using AMD's PowerNow! Technology. When this is enabled, Opteron power consumption drops to roughly 160 to170W when idling.

"To be fair, we could not get EIST to function with our new dual-core Xeons, which may help idle power consumption levels. However, their full-load levels are ghastly high."

That's a disturbing result for Intel, which has suddenly jumped on the performance per watt bandwagon after bragging for so many years that it could produce chips hotter than the surface of the sun. Apple CEO Steve Jobs justified his switch to Intel processors by arguing that, "future products can't be built on IBM's PowerPC. Intel has performance and better performance per watt. Intel delivers much better performance per watt."

Let's hope he has a flame retardant turtleneck.

To be sure, Intel is trying hard to move away from its power-hungry legacy, but as Paxville shows, green computing doesn't come easy. Oddly, Intel has admitted that Paxville isn't the most elegant dual-core chip on the market and expects most customers will wait for better performing Xeons due out in 2006.

Overheating? No more

Intel server chip chief Pat Gelsinger. Behind him, Paxville is caught during a critical phase of its boot sequence.

All of this gives rise to the question - why even release Paxville?

Don't look. Hot Carl just melted my box

Having a dual-core chip on the market will hopefully stop the Wall Street Journal and New York Times from writing that Intel trails AMD with dual-core chip technology. Those papers aren't going to describe the differences between dual-core designs. So that's a major victory at least from a marketing and investor point of view. Shareholders don't like to read negative copy about their companies in such respected papers.

On the other hand, you have publications such as GamePC actually testing these chips and showing that even the fastest Opteron (2.4GHz) consumes less power than the slowest Xeon (2.4GHz). This wouldn't be such a big deal if the fastest Xeon (2.8GHz) could crank software at a much quicker clip than Opteron.

But it can't.

The Opteron chips trounced the Xeons in every benchmark conducted by GamePC. In many cases, the worst performing Opteron part beat the best performing Xeon.

The reviews site diplomatically spun the results:

"Intel's 'Paxville' Dual Core Xeon processors can provide a much needed performance boost in applications which are designed to take advantage of a lot of processors and run a lot of simultaneous threads. Namely, server and high-end workstation class applications. In applications which can fully make use of its abilities, these new Xeon processors can push some solid performance numbers and crunch through code fairly fast."

Fine. And...?

"The amount of processing power with two of these Xeons is pretty impressive; however, all this processing power does come at a cost.

"Intel's new dual-core Xeon consumes the most power of any processors we've seen to date, and also runs exceedingly hot, both negative qualities for a processor which is designed for the server space. In addition, the chip is also not compatible with older Socket-604 platforms, meaning you will have to drop an additional $400-$500 on a new dual-core Xeon compatible platform, which will be a painful purchase if you've already got a Socket-604 Xeon system up and running today, and want to upgrade to dual-core processor. In addition, as of today, there are no motherboards on the market available to purchase which will support these new processors, which certainly will put a damper on any prospective buyers."

Oh. Surely, it's not that bad.

"Unfortunately, even a solid platform can't help Intel's performance numbers, as their new dual-core chips (while powerful in their own right) simply are bested across the board by AMD's dual-core Opteron processors. Even worse, the Opterons typically perform much better while running at slower clock speeds and only having half the amount of on-die L2 cache to utilize. AMD's chips also consume far less power and run quite a bit cooler, giving AMD an edge on nearly all fronts."

Yipes. Back to the labs, boys.®