AMD makes quad-core promise but refuses to talk performance

AMD has officially announced in a press briefing that it expects to be shipping its new ‘Barcelona’ Quad Core Opteron line of server processors to vendors in August, with general availability in early September.

Barcelona is the first ever ‘native’ quad-core CPU, with all four cores on one die, as opposed to Intel’s approach of putting a pair of dual-core dies in one physical package. However, even this close to release the company is still refusing to give concrete benchmark results in comparison to quad-core Xeons.

It did, however, reveal that the initial release would include parts running at up to 2GHz, and that both 95W and low-power 68W versions would be launched.

Opteron product manager Steve Demski deflected talk that 2GHz seemed low in the light of Intel’s higher-frequency parts: “We’ll put our 2GHz part up against their 2.33 and be happy with that all day long,” he said.

The company is vociferous in hammering home the point that the power envelope of the new parts is identical to the old (a requirement that, as we exclusively reported, has been responsible for much of the delay in Barcelona’s release); and that it’s a drop-in replacement for servers currently using Socket F Opterons with nothing more than a BIOS upgrade.

Continuing the current industry love affair with virtualization, a large chunk of the briefing focussed on Barcelona’s enhancements to increase virtual machine performance. Chief among these is a technique called nested paging, which takes some memory-management duties away from virtual-machine software and into hardware, reducing what AMD calls ‘world-switching’ times (the time taken to flip between virtual machines) by 25%, it says.

Claims that the absolute performance of the new CPUs is going to outstrip Intel’s highest-frequency parts were, however, conspicuous by their absence. Worldwide channel market development manager Felipe Payet was at pains to stress that “you need to compare apples to apples” and performance should be assessed in the context of cost and power consumption.

In addition, AMD admits single-threaded code remains Intel’s domain, since Intel’s architecture means a single core is able to use all available Level 2 cache, something the dedicated Level 2 complement of each Barcelona core doesn’t allow: “The nature of their cache does help on single-threaded code”, said Demski.

But the company remains bullish about the advantage of the cache setup when it comes to multithreading and multitasking, particularly with multi-processor systems. “We can’t wait to run our MP setup against theirs”, said Payet, pointing out that while Intel has had its quad-core Xeon DP chips on the market for some time, the MP parts will appear at roughly the same time as Barcelona, which is launching simultaneously in both DP and MP variants.

On the subject of Intel’s commercial tactics, AMD remains characteristically feisty. Claiming that Opterons have had the equivalent of Intel’s newly announced Flex virtual-machine migration feature for several years (but that AMD hasn’t shouted about it), Payet quipped that “Intel’s been pretty efficient recently at confusing the market”.