IMC frequency performance scaling:



As I already mentioned on the previous pages, the AMD processors have their memory controller build inside the processor to produce higher bandwidth and lower latencies. The memory controller has its 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: 3000MHz

HTT frequency: 200MHz

HT Link frequency: 1000MHz

Memory frequency: 400MHz (1:2 divider)

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

Variable:

Northbridge frequency: 1000-3000MHz


(Click for bigger version)

The biggest increase in performance can be found in the memory benchmark that measures the memory write bandwidth. In addition to the obvious increase in performance of the memory, we notice that the 3DMark01 benchmark also scales quite nicely: 20% up in FPS going from 1GHz to 3GHz.

For the people who are interested in tweaking their configuration for optimal SuperPi 1M performance, we can tell you that the IMC has a great effect on the so-called efficiency of your system. Underneath you can find a 1M result with an efficiency of 675xx, which is at the moment one of the most efficieny 1M runs on record.


(Clickable)

In overclocking circles, the efficiency is often mentioned when discussing the overclocker's skill to tweak his system. The 1M efficiency is calculated as follows:

Efficiency = Time (sec) x Frequency of processor (MHz).

The lower this value, the better as you need less cpu power to end the benchmark at a given time!