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Other => CPU/GPU Bitcoin mining hardware => Topic started by: qwertyegg on January 14, 2012, 09:44:25 AM



Title: help underclock asus non-reference hd 6950
Post by: qwertyegg on January 14, 2012, 09:44:25 AM
Hi everyone, I just bought this card

http://www.asus.com/Graphics_Cards/AMD_Series/EAH6950_DCII2DI4S1GD5/

And I'm trying to get the memory clocked at 300MHz or lower but seems I cannot do it.

I tried to edit the bios in RBE first, and whenever I edit the memory clock in "clock info 02" (which is supposed to be the lower bound of memory clock, in the case of hd 5870), I got a BSOD at windows start. I searched and found some explanation saying hd 6xxxx series bios is signed so when I edit that part and flash it back it found the mismatch and the driver would report error and then bsod.

Then I tried to use the asus smartdoctor. I can tune the vCore of this card(cannot in afterburner), but the lower bound of memory is stuck at 1050MHz. I'm wondering if there's a way to change the lower bound of this memory clock in smartdoctor.

After that, I was tweaking in the amd overdrive and afterburner. The lower bound for both of them are 625MHz, which is good. But the problem here is whenever I set the clock under 825MHz, the memory clock is actually running at 1250MHz, which is the card default. For example, I set the memory clock 810MHz, the actually running memory clock is 1250MHz; I set the memory clock 625MHz, the actually running memory clock is 1250MHz. But when I set the memory clock 825MHz, the actually running memory clock would run at 825MHz.

How can I lower the memory clock of this card?


Title: Re: help underclock asus non-reference hd 6950
Post by: P4man on January 14, 2012, 10:33:16 AM
I dont think its possible on radeon 6 cards. You can underclock the ram only a few 100 MHz, as far as I know.


Title: Re: help underclock asus non-reference hd 6950
Post by: bulanula on January 14, 2012, 11:33:54 AM
I dont think its possible on radeon 6 cards. You can underclock the ram only a few 100 MHz, as far as I know.

Serves the OP right for not doing his research.

Only 5xxx series benefit from underclocking the RAM and other tweaks like SDK 2.1

6xxx series are to be avoided unless you can't get hold of any 5xxx cards.


Title: Re: help underclock asus non-reference hd 6950
Post by: SlaveInDebt on January 14, 2012, 12:15:00 PM
Use Sapphire Trixx.


Title: Re: help underclock asus non-reference hd 6950
Post by: jake262144 on January 14, 2012, 01:24:19 PM
Hi everyone, I just bought this card

http://www.asus.com/Graphics_Cards/AMD_Series/EAH6950_DCII2DI4S1GD5/

And I'm trying to get the memory clocked at 300MHz or lower but seems I cannot do it.

I tried to edit the bios in RBE first, and whenever I edit the memory clock in "clock info 02" (which is supposed to be the lower bound of memory clock, in the case of hd 5870), I got a BSOD at windows start. I searched and found some explanation saying hd 6xxxx series bios is signed so when I edit that part and flash it back it found the mismatch and the driver would report error and then bsod.

Then I tried to use the asus smartdoctor. I can tune the vCore of this card(cannot in afterburner), but the lower bound of memory is stuck at 1050MHz. I'm wondering if there's a way to change the lower bound of this memory clock in smartdoctor.

After that, I was tweaking in the amd overdrive and afterburner. The lower bound for both of them are 625MHz, which is good. But the problem here is whenever I set the clock under 825MHz, the memory clock is actually running at 1250MHz, which is the card default. For example, I set the memory clock 810MHz, the actually running memory clock is 1250MHz; I set the memory clock 625MHz, the actually running memory clock is 1250MHz. But when I set the memory clock 825MHz, the actually running memory clock would run at 825MHz.

How can I lower the memory clock of this card?

(1) This card allows up to 125 MHz difference between core and memory clocks.
         You can set the memory clock to gpu_core clock -125.

(2) Yeah, you can forget RBE tricks
(3) Only ASUS smartdoctor is able to modify the voltages.

ASUS have outdone themselves in going full retard custom with this sodding thing.


Title: Re: help underclock asus non-reference hd 6950
Post by: qwertyegg on January 14, 2012, 07:12:55 PM
Thanks guys, seems saphire trixxx is my last straw I'm gonna try it out and post the results here.


Title: Re: help underclock asus non-reference hd 6950
Post by: qwertyegg on January 14, 2012, 07:32:25 PM
OK, I tried to drag the memory clock to 400MHz, lower bound of saphire trixxx. OS freezed. After restarting and re-open the trixxx, I found it locks my vCore at crazy 1.68V and shows only 793mV.

This looks pretty dangerous to me I guess I will just live with the asus smartdoctor with 1050MHz mem clock.


Title: Re: help underclock asus non-reference hd 6950
Post by: jake262144 on January 14, 2012, 07:49:50 PM
OK, I tried to drag the memory clock to 400MHz, lower bound of saphire trixxx. OS freezed. After restarting and re-open the trixxx, I found it locks my vCore at crazy 1.68V and shows only 793mV.

This looks pretty dangerous to me I guess I will just live with the asus smartdoctor with 1050MHz mem clock.

Dude, what's your gpu clock?
As I told you, any third-party program (like cgminer) is able to set memory to gpu core clocks minus 125MHz. If you OC'd to 930, you can easily set memory at 805.
It's just impossible to go lower than that.

Please don't mess around with trixxx as that's potentially lethal: this card sports a fully custom VRM, god only knows what values should be loaded into which registers and how they are interpreted bt the card's BIOS. In theory, you could unwillingly set GPU core to 1.5 volts and fry it alive.


Title: Re: help underclock asus non-reference hd 6950
Post by: AniceInovation on January 17, 2012, 12:43:57 PM
I have been lucky setting my 6950 memories to 300 using cgminer on windows.
Can't say the same with BAMT.


Title: Re: help underclock asus non-reference hd 6950
Post by: jake262144 on January 17, 2012, 01:39:19 PM
I have been lucky setting my 6950 memories to 300 using cgminer on windows.
Can't say the same with BAMT.

device_id=="ASUS EAH6950_DCII2DI4S1GD5" || OT post.
http://www.asus.com/Graphics_Cards/AMD_Series/EAH6950_DCII2DI4S1GD5/ (http://www.asus.com/Graphics_Cards/AMD_Series/EAH6950_DCII2DI4S1GD5/)