Early word on AMD's Barcelona chips: More efficient than powerful

AMD released its long-awaited Barcelona server chip today while Intel upped its earning forecast, underscoring the importance of AMD's latest release. AMD has lost ground in the server market since Intel launched its Core architecture, and things are even more one-sided with desktops and laptops with Intel's Core 2 Duo processors dominating the scene. While AMD has stated it will role out Barcelona chips for desktops under the Phenom name in December, it released new Opteron server chips today based on its native quad-core architecture.

Unlike Intel's quad-core Xeon parts, which simply package together two dual-core processors, AMD's Barcelona chips feature four processing cores on a single piece of silicon, which, according to AMD, results in better performance. In addition to adding a unified L3 cache and bringing improvements to its famed integrated memory controller, AMD also introduced a number of features to improve the chip's energy efficiency. Areas of the processor are turned off when not needed via CoolCore, while Independent Dynamic Core Technology means that each core can adjust its clock speed so that they're not running any faster than necessary. The CPU cores and the memory controller use separate power planes so that each draws only the wattage it needs.

Also helping AMD push the lower power consumption angle is the fact that the chips are clocked slower than many expected. The 2.0GHz Opteron 2350 is the speediest of the chips introduced today, though higher clocked parts are expected to be rolled out in the coming months. Does it all add up to a winner for AMD? The early returns are mixed. While the Barcelona chips are competitive with Intel's current quad-core Xeons and live up to the lower power consumption claims, they don't seem to be the runaway hit AMD had hoped.

The Tech Report tested a number of the new Barcelona chips, including a preview of a 2.5GHz Opteron chip that's not due out till the end of the year. It found some latency issues with Barcelona's L3 cache, less than enthralling floating-point performance, and up and down performance on the whole. It concluded, "Barcelona's gains in performance per clock aren't quite what we expected, especially in floating-point-intensive applications like 3D rendering, where it looks for all the world like a quad-core K8. As a result, Barcelona is sometimes faster, sometimes slower, and oftentimes the equal of Intel's Core microarchitecture, MHz for MHz. Given the current clock speed situation, that's a tough reality." That is, if you want a faster quad-core server part than what you can get in the Opteron line, you can find it among Intel's Xeon line.

AnandTech tested the 2.0GHz Opteron 2350 and found it performed on par with a pricier Xeon chip. It also reported that it was very energy efficient. And in simulating a desktop environment to get a glimpse at the potential of the Phenom processors, it found that Phenom offered "much improved" gaming performance and a 10 percent to 15 percent overall performance advantage compared with a similarly clocked Athlon 64 X2. It'll take more than that to unseat Core 2 Duo in desktops, however. As for the server chips rolled out today, Anand concluded that "AMD hasn't clearly hit a home run this time, but at least they're playing in the same ballpark."

If you'll allow me to continue the metaphor, the problem of AMD showing up for a game against Intel now is that Intel has nearly completed a new stadium. Intel's 45nm Penryn chips are expected on Nov. 11. Perhaps AMD can raise its revenue outlook on that date to return the favor.