Lowering mem clock to idle speeds SPEEDS UP Mh/s

[nster]

My guess is this works for all ATI cards (4XXX and up) but it may only work for certain cards only

I've tried countless test, and I've concluded that for my 6870 at least, I get up to 5% Mh/s increase by forcing idle clock for mem (300 from 1050). All tests I have done are with OCed core clock (1000~1045 from 900)

I used MSI afterburner. At 250 mem clock I got a 10% DECREASE, at 900~1200 mem clock I get a 5% DECREASE from mem clock at 300

Give it a try

http://event.msi.com/vga/afterburner/download.htm

Go in your MSI afterburner folder in program files (X86 for me) and edit the msiafterburner.cfg

where you see [ATIADLHAL] make sure it looks like this:
[ATIADLHAL]
EnableUnofficialOverclocking   = 1
UnofficialOverclockingEULA   = I confirm that I am aware of unofficial overclocking limitations and fully understand that MSI will not provide me any support on it
UnofficialOverclockingMode   = 2
AccessibilityCheckingPeriod   = 0

in order to get lower memory clocks please follow this:

1- Open MSI Afterburner
2- Set Memory Clock to the lowest possible or to desired amount
3- Click Apply
4- If Memory Clock is not to the desired amount, close MSI Afterburner
5- Repeat 1 to 4 until desired amount is reached
6- Set Fan Speed

Same can be done to get higher core clocks

Donations are always welcome 167q1CHgVjzLCwQwQvJ3tRMUCrjfqvSznd

EDIT: It seems the most effecient memory clock is between 300 and 400. In my case, for 1020 core on a 6870 it is 344, you should experiment as well

[nster]

Got the unofficial clocks enabled.

I can get only as low as 525 @ MC.

But holy smokes I get now 256Mh/s on both of my sweeties.
Also my drivers crash occasionally, but 1000 @ CC seems to be the max for mysetup. no idea why, anything more crashes the drivers.

Thanks for the tip will be sticking @ low-MC from now on.

no problem.... in order to get lower memory clocks please follow this:

1- Open MSI Afterburner
2- Set Memory Clock to the lowest possible or to desired amount
3- Click Apply
4- If Memory Clock is not to the desired amount, close MSI Afterburner
5- Repeat 1 to 4 until desired amount is reached
6- Set Fan Speed

Same can be done to get higher core clocks

[Beremat]

5870 here.

Going from 1200->275 mem makes no difference, and 275->900 makes it run 2-3 mhash higher, but the card is a lot louder and hotter at this setting as well.

[nster]

So each card probably has a sweet spot for mem clock

[nster]

@nster , you need to start hanging out on IRC.

Download http://xchat.org/ and join us at Freenode network. Channels: #bitcoin-discussion , #bitcoin-dev , #bitcoin-otc , #bitcoin-monitor and many more.

Just went there

I just restarted my comp and my Mh/s are back to normal, before, my Mh/s were 5% lower than usual for no apparent reason. Also, my CPU mining doesn't really affect my GPU mining anymore (before it would lower it by 10Mh/s, not it lowers it by 1 if not less

[dishwara]

@nster , you need to start hanging out on IRC.

Download http://xchat.org/ and join us at Freenode network. Channels: #bitcoin-discussion , #bitcoin-dev , #bitcoin-otc , #bitcoin-monitor and many more.

If it is said here in bitcoin forum, instead on IRC, it stays forever, (until mods deletes), so not only advanced, but also new , no voice user found it useful.

[ATIADLHAL]
EnableUnofficialOverclocking   = 1
UnofficialOverclockingEULA   = I confirm that I am aware of unofficial overclocking limitations and fully understand that MSI will not provide me any support on it
UnofficialOverclockingMode   = 2
AccessibilityCheckingPeriod   = 0

UnofficialOverclockingEULA   =1 ,i put & cant make it to work MSI. thanks for saying that i have to write a long sentence & promise MSI.

[nster]

@nster , you need to start hanging out on IRC.

Download http://xchat.org/ and join us at Freenode network. Channels: #bitcoin-discussion , #bitcoin-dev , #bitcoin-otc , #bitcoin-monitor and many more.

If it is said here in bitcoin forum, instead on IRC, it stays forever, (until mods deletes), so not only advanced, but also new , no voice user found it useful.

[ATIADLHAL]
EnableUnofficialOverclocking   = 1
UnofficialOverclockingEULA   = I confirm that I am aware of unofficial overclocking limitations and fully understand that MSI will not provide me any support on it
UnofficialOverclockingMode   = 2
AccessibilityCheckingPeriod   = 0

UnofficialOverclockingEULA   =1 ,i put & cant make it to work MSI. thanks for saying that i have to write a long sentence & promise MSI.

I think he meant just to talk because he likes my posts so far...

As for the 2nd part could you rephrase? I did not get it. For some people the =1 is fine, for others you gotta write the whole thing, so I just gave you the long version

[dishwara]

I think he meant just to talk because he likes my posts so far...

As for the 2nd part could you rephrase? I did not get it. For some people the =1 is fine, for others you gotta write the whole thing, so I just gave you the long version

u may be right. before i tried with 1 & it didnt help MSI to OC. Now after that long sentence, i can able to go to 300Mhz from 1050Mhz of mem clk & i have to thank u for creating this post.
By decreasing mem clk, i dont see much difference in Mhash/s , may be i didnt look carefully.
But it helped me to lower temp.
I have 6870 & running at 1038 core clk, 1050 mem clk, 100% fan & getting 265-268 Mhash/s with temp 74-75C.
Now with 1038 core clk, 325 mem clk, 100% fan, i am getting 267-269 Mhash/s with temp 65-66C.
around 10C reduction in temp by lowering mem clk, which i never expected.

[nster]

I think he meant just to talk because he likes my posts so far...

As for the 2nd part could you rephrase? I did not get it. For some people the =1 is fine, for others you gotta write the whole thing, so I just gave you the long version

u may be right. before i tried with 1 & it didnt help MSI to OC. Now after that long sentence, i can able to go to 300Mhz from 1050Mhz of mem clk & i have to thank u for creating this post.
By decreasing mem clk, i dont see much difference in Mhash/s , may be i didnt look carefully.
But it helped me to lower temp.
I have 6870 & running at 1038 core clk, 1050 mem clk, 100% fan & getting 265-268 Mhash/s with temp 74-75C.
Now with 1038 core clk, 325 mem clk, 100% fan, i am getting 267-269 Mhash/s with temp 65-66C.
around 10C reduction in temp by lowering mem clk, which i never expected.

Try 300 mem clock exactly...

Yea temp reduction helps... though you temps are high for 100%... I get those temps with 57% fan and with 1045 core

[dishwara]

mem clk 300 don't do much. but for me mem clk 375 gives 271-273 Mhash/s & any other mem clk gives less, 265-270 only.

[JWU42]

@nster , you need to start hanging out on IRC.

Download http://xchat.org/ and join us at Freenode network. Channels: #bitcoin-discussion , #bitcoin-dev , #bitcoin-otc , #bitcoin-monitor and many more.

Just went there

I just restarted my comp and my Mh/s are back to normal, before, my Mh/s were 5% lower than usual for no apparent reason. Also, my CPU mining doesn't really affect my GPU mining anymore (before it would lower it by 10Mh/s, not it lowers it by 1 if not less

Use the freeware version of xchat -- http://code.google.com/p/xchat-wdk/

[niooron]

Isn't this just a buggy overclocking tool? You can just use AMDs GPU clock tool if you want to overclock beyond the Overdrive limit.

[nster]

Isn't this just a buggy overclocking tool? You can just use AMDs GPU clock tool if you want to overclock beyond the Overdrive limit.

So far MSI's Afterburner is the best OC tool I've used

[nster]

So many people have benefitted frpom this yet noone feels the urge to donate? 

[nster]

Anyone else wants to share their experience? be it if it just lowered your temp by 10C or if it actually gave you an Mh/s increase?

Thanks person who donated 0.5 btc the 1st donation I ever received 

[qed]

Lowering the memory clock is lowering your hash/s by a very small %. From me, from 1250 MHz to 625 MHz is decreasing my performance by something smaller than 1%.

My 3 HD 6950 are on underclock (725 MHz core, 625 MHz ram) and undevoltage since the beginning. The overall system consumption is around 350W insted of 650 W for a 10% higher has rate.

[nster]

Lowering the memory clock is lowering your hash/s by a very small %. From me, from 1250 MHz to 625 MHz is decreasing my performance by something smaller than 1%.

My 3 HD 6950 are on underclock (725 MHz core, 625 MHz ram) and undevoltage since the beginning. The overall system consumption is around 350W insted of 650 W for a 10% higher has rate.

Interesting... with my 6870, my hashrate went up ~5Mh/s AT LEAST... so somewhere around 2~3%, and my temps by 5~10C I'm not too sure (my fan speed varies)

[bbulker]

Sent a donation, thanks for the tip. Lowered my temps from 72C to 67C on my 6850. The hashrate did not lower either.

[gjs278]

the hash rate on poclbm in linux on a 5870 lowers drastically (a good 10mhs) when the memclock is at 300 compared to 900. you can do it with radeon bios editor though, since MSI afterburner isn't available in linux.

[nster]

I'll bump this for whomever missed it before