Benchmarks: AMD's 45nm 'Shanghai' Opteron

Summary: AMD's 'Shanghai' processors are the company's first chips to exploit the improved performance and efficiency of 45nm technology. ZDNet's tests show that they have made up important ground on Intel's Xeons.

By Christoph Hochstätter | November 20, 2008 -- 13:46 GMT (05:46 PST)

Locking down the instruction set for virtualisation compatibility
With Shanghai, it's now possible to lock down the instruction set to a subset of the full complement. This feature is important in the live migration of virtual machines (VMs), using, for example, VMware's VMotion. If a VM is moved from one piece of hardware to another in a live environment, it could crash if certain instructions are suddenly no longer available.

If the instruction set is limited to SSE2 when starting a VM, then the VM can be moved to any server that uses at least a Pentium 4. Since Intel's newest processors — for example, the 6-core 'Dunnington' Xeon — also offer instruction set lock-down, it should now be possible to move VMs between live AMD and Intel systems — something that would have unthinkable until recently.

Of course, that instruction set lock-down means accepting the lowest common denominator. But in practice less than five percent of all standard software uses instructions outside SSE2, so a performance hit is unlikely.

The new Shanghai Opterons all consume 75W of Average CPU Power (ACP) — which corresponds to about 95W of Thermal Design Power (TDP) — and are available with clock speeds ranging from 2.3GHz to 2.7GHz. AMD will be releasing 55W models and a 105W chip running at 2.8GHz in the first quarter of 2009.

Prices for the CPUs for two-socket motherboards start at $377 for 2.3GHz, rising to $989 for 2.7GHz. The almost identical CPUs for four- and eight-socket boards are significantly more expensive: $1,165 for the 2.4GHz model and $2,149 for 2.7GHz.