On Figure 1 you can see a chart provided by Intel comparing a 3.33 GHz 64-bit Xeon MP with 8 MB L3 memory cache performance with a 3.66 GHz 64-bit Xeon MP with just 1 MB L3 memory cache. As you can see, for applications that really need Xeon MP processors, like SAP and Oracle, it is better to have a bigger L3 memory cache than a higher clock rate.

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Figure 1: 3.33 GHz 64-bit Xeon MP with 8 MB L3 memory cache vs. 3.66 GHz and 1 MB L3 memory cache.

Another advantage of this new Xeon MP model is its scalability. When we install more than one processor in a server, the server performance is not multiplied by the number of available processors. I.e., a system with two Xeon processors isn't twice faster than a system with just one. According to Intel, the performance will increase between 1.59x and 1.92x, depending on the software used. In the case of four CPU configuration, the increase in performance varies between 2.14x and 3.52x, once again depending on the used software.

But with 64-bit Xeon MP the performance gain when we install more than one CPU is greater than the one obtained with the previous Xeon MP generation, reaching up to 3.96x in a system with four CPUs and up to 1.99x in a system with two CPUs, so with this processor the idea of the performance to be multiplied by the number of CPUs available is more likely. We show this on Figure 2.

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 Figure 2: Increase in performance due to the increase on the number of processors on the system.