AMD Opteron 275

Among the CPUs AMD offers for dual-processor workstations are also dual-core solutions. There are quite a few processors like that in the market today: the frequency of these models ranges from 1.6 to 2.4GHz. We were lucky to get the 2.2GHz model known as Opteron 275. This is not the senior model in the series, but it should give us enough information about the capabilities of dual-processor systems based on dual-core CPUs.

However, we have to point out right away that these were actually, not the Opteron 275 CPUs, but Opteron 875 from a more heavy-weight category. This doesn’t make any difference to our today’s experiment, because the latter is initially targeted for multi-processor configurations, but performs exactly alike to the Opteron 275 in a dual-processor system.

Dual-core Opteron processors are based on Egypt core (for the 800 series) or Italy core (for the 200 series) depending on the type of systems the CPU is intended for.

The Opteron 875 CPUs that we tested were marked as OSA875FKA6BS. It means their core is the E1 stepping and is similar to the Toledo core of the desktop Athlon 64 X2. The architecture of the dual-core Opteron doesn’t differ from the Athlon 64 X2 architecture: they both have two cores with two separate L2 caches, but share a single integrated memory controller and a single HyperTransport bus controller.

The cores of all dual-core Opterons are manufactured on 90nm tech process, have two 1MB L2 caches and support the SSE3 instructions set. The Opteron 275 (and 875) model has a clock rate of 2.2GHz and thus resembles the Athlon 64 X2 4400+. Unlike the desktop processor, the Opteron is installed into Socket 940 and has three HyperTransport buses, and its integrated memory controller supports registered DDR SDRAM.

The specification of the Opteron 875 processor we used in our tests is listed below:

We should note that like the Opteron 254, the Opteron 875 dissipates less heat than its desktop mate, and this allows using dual-core Opterons on the mainboards single-core CPUs of this class are installed on. Older mainboards just need a BIOS update to support the dual-core models.

Here’s what CPU-Z told us about the system with two Opterons 875:

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The OS installed on the platform with two dual-core Opteron 275 (875) CPUs is going to identify four logical processors.