Northbridge IMC frequency performance scaling:



As I already mentioned on the previous pages, the AMD processors have their memory controller built inside the processor to produce higher bandwidth and lower latencies. The memory controller has it's own frequency, not linked to either CPU frequency or even memory frequency, but linked to the HTT frequency, which is the base clock frequency from which all other frequencies are derived. Using a multiplier, you can increase or decrease the frequency of the memory controller to obtain more performance.

Test settings:

Core frequency: 2800MHz

HTT frequency: 200MHz

HT Link frequency: 1000MHz

Memory frequency: 400MHz (1:2 divider)

Memory timings: 4-4-4-10 2T Ganged

Variable:

Northbridge frequency: 1000-2400MHz

Note that we testing the frequency of the memory controller, NOT the northbridge itself


(Click for bigger version)

Unlike what most of you would expect, the IMC frequency has quite an effect on the performance of the different tests. Remarkably, the write bandwidth skyrockets when increase the IMC frequency, which we didn't see in the other performance scaling tests (which did show us an increase in read and copy bandwidth). Also noteworthy is the increase in 3DMark01 Nature: about 20%.