AMD offers Opteron 2XX processors for the dual-CPU system configurations. Among them there are three dual-core models today: Opteron 265 working at 1.8GHz, Opteron 270 working at 2.0GHz and Opteron 275 working at 2.2GHz. We were trying to get a pair of the latter for our today’s tests.
Luckily, our efforts were not vain: we managed to get hold of two dual-core Opteron CPUs working at the actual 2.2GHz frequency. However, these were not the 275 models, but the CPUs from a more heavyweight category: Opteron 875. Although it doesn’t really matter for our today’s investigation, whether we have Opteron 275 or Opteron 875 installed into our system, because the only difference between them is the ability of the “heavyweights” to work in multi-processor systems. As for the dual-processors systems, these CPUs perform identically.
As you can see from the picture above, the OPN of the Opteron CPUs we got was OSA875FKA6BS. Unfortunately, we didn’t find this particular model specification on AMD’s official web-site, however, if we read and decode this marking, we will get the following details:
Dual-Core AMD Opteron™ Processor Details
Dual-Core AMD Opteron™ Processor Model 875
Ordering Parts Number (OPN)
HyperTransport Technology Speed
Integrated Memory Controller
L2 Cache Size
2 x 1 MB
L2 Cache Speed
.09 micron SOI
This Opteron processor has the maximum working frequency for a dual-core solution: 2.2GHz. In other words, the CPUs that we will be testing today’ are the fastest solutions of the kind. Note that dual-core Athlon 64 X2 CPUs for desktop systems have already reached the frequencies higher than that. For instance, Athlon 64 X2 4800+ and Athlon 64 X2 4600+ work at 2.4GHz. No doubt that AMD doesn’t hunt for higher clock rates with these processors, because they prefer to keep these server and workstation solutions within the standard thermal range of 95W. As for the typical heat dissipation of the 2.4GHz CPUs from AMD, it rests around 110W today. Server and workstation platforms cannot heat up that much.
The diagnostic CPU-Z utility reports the following details about our Opteron 875 processor:
This utility recognizes correctly the 1MB L2 cache of each processor core. This Opteron CPU is based on E1 core revision. In other words, this processor belongs to the E core stepping CPU family and hence supports SSE3 instructions.
All in all, the dual-core Opteron architecture is very similar to that of the dual-core Athlon 64 X2 processor. The difference is in the memory controller and the number of HyperTransport busses.
Even though the Opteron processors have a dual-channel memory controller, they work only with Registered DDR DIMM modules. As a result, they allow more system memory than their desktop counterparts. However, you have to sacrifice speed for the sake of larger memory capacity, because Registered memory modules are usually slower and do not support very aggressive latency settings.