Are Three Cores Better Than Two?

It Works! Sort Of

It looks strange, but it actually worked.

Looking at the performance tab of the Windows Task Manager is rather strange if it shows three processors running. But who cares, it seemed to be working well and we began benchmarking.

Of course, we used our complete benchmark suite and we actually found some programs that were not working properly. Pinnacle Studio Plus 9.4.3 crashed repeatedly. Auto Gordian Knot, which we use for encoding DivX or XviD video, could not start the encoding process because it obviously was not able to access our AVI file. PCMark crashed sometimes right after finishing the compression test.

The problems are due to two processors types that are very different. Although both run at a 2.2 GHz clock speed, the single- core Opteron 248 is based on the 130 nm Sledgehammer design, while the dual-core Opteron 275 is a 90 nm Venice dual- core chip.

These two processors do not only differ in the manufacturing process: Changes to the memory controller have been made during the transition from 130 to 90 nm and SSE3 extensions were added. Opteron 248 was designed for HT800 (200 MHz bus), while the Opteron 275 is capable of running HT1000. Finally, the cache size per core is different as well.

Picking processors for dual-CPU machines sometimes was difficult in the past, because these often had to be at least the same product type, if not identical in order to run. All these facts we listed now basically made it unlikely that our asymmetric system would even be able to boot.

The fact that it worked served to prove that a triple-core system based on the same cores would only offer better results.

PCMark05 was not quite able to detect the correct processor configuration. It displays one physical processor with as many as three logical ones.