Some Windows users have stated being able to underclock the memory by greater than 150 MHz below the core speed using MSI Afterburner. Is this simply an artifact of the software? That is, is the actual memory speed only 150 MHz below the core, but the software reads whatever the user sets it to?
I use MSI AB to lower the memory clock down to 375. This is confirmed in CGMiner, and in GPU-Z (on the sensors tab, which reads actual values). I also notice a temp and power drop when I do it. It does work.
It does also reduce power consumption measurably. I got about 15w/card going from 685->340mhz
It is also not very easy to enable. I havent been able to reliably replicate the process. I have done it on 2 machines and cant for the life of me get it to work on the 3rd. Not quite sure what is different, I even copied the exact MSI AB files (config and bins) across.
I don't remember the numbers off the top of my heat, but with my core at 1200, moving my memory from 1050 to 325 did make a drop of about 4C. The higher your mem clocks go, the more power they use (due to higher voltages). I wanna say it was ~30W going from 1500 to 1050, and then another ~20 moving from 1050 to 375.
I got a bigger power saving from undervolting, tho. I dropped my core down to 1050, and moved the MSI AB slider to 1050mV, and the card pulls around 615MH/s @ 140W.