Underclocking ATI Memory to reduce heat??

[zombo]

Hi I heard about underclocking my ATI's memory to reduce heat. I have 2x 6870's and they are sitting at about 75 celcius ( is this too hot? )

I was wondering how do I go about underclocking the memory?

Right now my Core is at 950 (overclocked) and memory is at stock and cannot be set lower in the catalyst control center.

[ND]

Install MSIAfterburner and enable ati overdrive on catalyst control center panel. Then use Afterburner to downclock your memory (You can overclock on afterburner if you want, no need to use the catalyst control center.

[eddd]

I haven't noticed any decrease in GPU temperature via underclocking memory.

However, when I underclock my memory down to 300mhz, I gain around 10mh/s - this is on my ATI 4850.

[zombo]

Strange how you gained, thanks for MSI afterburner its working great Underclocked memory about 300 mhz and increased clock to 980 pulling 300mhash per card !!

[ND]

Is a known fact that undercloking the memory to 300 can raise the mh/s.

[shata]

Strange how you gained, thanks for MSI afterburner its working great Underclocked memory about 300 mhz and increased clock to 980 pulling 300mhash per card !!

Im pushing 369mhash using 940/685 on 6970 2gb card, and yes underclocking gave me about 10-15mhash depends. Also heat went down about 2c.

[Patheos]

I am able to get a pretty constant 370-380 Mh/s with my 5870 running the clock speed at 900mhz, the ram at 900mhz and the fan at 100%.  I generally hover around 71 C.  I am just using the CCC AMD Overdrive software.  I am not sure if underclocking the ram really does anything or not. for heat, but I do it anyway.

[helikatze]

I'm using a Sapphire 6870 with 980GPU and 300mem settings and I'm getting 280Mh/s with the temp hovering in around 70c.

Underclocking the memory gave me a total of maybe 1-2 degrees lower temperature.

No increase on the Mh/s here....
:-(

[bgalakazam]

I have a HD 5770 and can only underclock memory to 650 in MSI Afterburner and 1200 in CCC.

Help?

[helikatze]

I'm using a Sapphire 6870 with 980GPU and 300mem settings and I'm getting 280Mh/s with the temp hovering in around 70c.

Underclocking the memory gave me a total of maybe 1-2 degrees lower temperature.

No increase on the Mh/s here....
:-(

Give "AMD GPU CLOCK TOOL" a try. Real performance gain happens at ~180 MHz for my 6870s, the make about 305 MHash/s. Do you raised your GPU-Clock? If not raise it by 3% and let it run for a while, than test 4% and so on. Than you will make the 300.

I'm working with an 80Mhz increase on my GPU (It was 900Mhz out of the box).

If I go more than 1000Mhz  I see little difference on the Mh/s increase and huge on temp. I will give a try with a different miner (poclbm right now). Maybe that will do the trick.

[bgalakazam]

As you can read some lines above: AMD GPU CLOCK TOOL

Thank you so much.

[benzz]

i would imagine you would use less power therefore less heat, or even if that doesnt work use up the extra free power to increase the core clocks for a more powerful miner

[o_dima]

Tried to underclock Memory on Asus EAH5850(725MHz) with AMDOverdriveCtrl 1.2.0 (ubuntu 10.10) but maximum stable values that I get:
GPU 885 MHz
Memory 620 MHz
if overlocking GPU to 890MHz or underclocking Memory to 600 MHz - it freezes completelly in several minutes...
So runing now with settings above - got 325Mhash and 69-70 celcius
Do anyone have an idea - can I get much performance? Or it is the ceiling values for me?

[kripz]

Is a known fact that undercloking the memory to 300 can raise the mh/s.

Anyone know why this is?

[XPiRX]

Is a known fact that undercloking the memory to 300 can raise the mh/s.

Where is your proof/evidence of this?  I'm running a 5870 with 950 core overclock and 1300 memory overclock which I lowered back to stock since it produced no increase in gaming performance or mining performance. I lowered the memory down to 800, 600, and 300.  Each time I gained no MHash/s, I actually lost about 1-2MHash/s each step I took down. I gain probably 1-2Mhash/s when I overclock to 1300 which isn't a big enough gain to bother with the extra heat. I'm using aftermarket cooling however (Artic Cooling Accelero Xtreme) so my temps max out at around 48-50 for all sensors overclocked (don't even see heat increase/decrease for memory with changes).

[o_dima]

...
if overlocking GPU to 890MHz or underclocking Memory to 600 MHz - it freezes completelly in several minutes...
...

I could not imagine, why to low Memory clock stucks the gpu. I think you gpu core clock is still to high. Overclocking is not an exact thing, you need time to find stable values. My 5850s do only 820 MHz without raising the vcore. Another thing is your power source. Don't think that you are good if you have a 500 watt source in your machine. You have to take a look at the values: 12V+, how many Amps you can take there? A single gpu should not be a problem, but 2 or more ... - surely.

Give AMD GPU CLOCK TOOL a try, set memory to about 180 MHz and core clock to 850, let it run for 2 days and your have a good start.

My power source - 600W, single GPU. Well thanks - will keep playng with settings, but I'm not the only one who have problems with underclocking Memory