AMD Drops More Details on Barcelona

SAN FRANCISCO — Advanced Micro Devices (AMD) opened up about Barcelona just a bit more today, providing more technical details on its upcoming quad-core server processor on how it can achieve up to an 80 percent power savings over the existing dual-core Opteron line.

AMD  made the presentation today at the International Solid State Circuits Conference (ISSCC) here. About the only thing left for AMD to disclose is the clock speed, but all it will say is the initial release of quad-core Opterons will be slower than dual core.

“We’re actually getting more performance by getting more design via IPC (instructions per cycle) and floating point. It’s not just about clock frequency; we’ve been saying that for a while,” Pat Patla, director of server workstation business for AMD, told internetnews.com.

AMD’s PowerNow! power management technology has been tuned and optimized for the quad-core CPU to provide more fine-grain control. Barcelona will feature faster switching between power states and more demand-based switching, so power needs can be determined based on load.

In previous CPUs, the cores were throttled together, so they both ran at the same power level despite differing loads. Barcelona will have four independent timing clocks, so the cores can be monitored and matched based on workload. If two cores are running, then the other two can go into an idle state, according to Patla.

AMD also brought power controls to the northbridge and memory controller. The northbridge and memory controller can also be monitored for power needs to turn functions on and off.

For example, if it notices that the memory controller is in a read-only state, it powers down the write state until needed. This can mean up to an 80 percent power reduction on many workloads.

AMD remains on track to ship the Barcelona processors by the middle of this year.