More Multi-core Memory Testing

27 May More Multi-core Memory Testing

As mentioned previously, I have been planning to benchmark some new low power AMD and Intel Quad cores. My motivation is the Limulus Project. Even though these processors are low-power desktop devices they work similarly to their big brother HPC versions. When Intel or AMD make a processor line “the guts” are basically the same. The marketing department slices and dices some of the features configuring products to reflect the market in which they will be sold. Servers need features that consumer desktops do not (and vis-versa). Some of these options make sense from a technical standpoint, while others are just marketing gymnastics.

The underlying architecture (the guts) are the same, however. Generational advances (like memory architecture) travel through the whole product line. The high end server processor may work 20% faster than the lower end desktop processors, but the cost is usually much more (almost always more than 20%). Thus, by using lower cost desktop parts, a large percentage of the “high end” performance can be had at a low end price. The Limulus project is designed to take advantage of this marketing trend. And, to be clear, the Limulus project is not a replacement for a large server based cluster.

Back to the issue at hand, however. I just finished testing the following desktop processors:

• Intel Core2 Quad-core Q6600 running at 2.4GHz (Kentsfield)
• AMD Phenom II X4 quad-core 910e running at 2.6GHz (Deneb)
• Intel Core i5 Quad-core i5-2400S running at 2.5 GHz (Sandybridge)

Note that the 910e and i5-2400S are 65W processors, which are necessary for the Limulus design. Each is in a single socket desktop motherboard. I described my testing script and procedure in a previous post. I ran my effective processor script on all three systems and recorded the results in the following table.

Effective cores for NAS Parallel Kernels

The results show a clear improvement over the Q6600 by both newer processors (due to better memory architecture). Interestingly, the 905e and the i5-2400S show about the same number of effective processors suggesting that the memory designs (each has two memory channels) are similar. Of course, the server version of these processors have more memory channels, better performance, and a higher cost. In the future, I’ll be running more tests with real applications.