Graphic Cards Need help to Undervolt HD6850 GPU

Mechanic

Mechanic

Skilled
Hi guys

I have a Sapphire HD6850 GPU in my system

I need to Undervolt my GPU and or Underclock it by a little bit

to cope with the searing summer heat

The 6850 at stock settings idles at 45C and jumps to 67C under Gaming load

I will just be playing some old games like Half Life 2 series and Bioshock and Mass Effect at 1600x900 res all summer long

so i wouldn't need the extra muscle at my disposal:)

My config is as follows

Athlon II X4 635 (undervolted to 1.25V)Stable

Corsair VX450

CoolerMaster Elite 310 Cabinet with pre-installed back exhaust

2xCoolerMaster BladeMasters to be added later
 
The 6850 at stock settings idles at 45C and jumps to 67C under Gaming load
Click to expand...

67C is very very cool man don't worry.

Okay, I presume it's the stock card. So here:

1. DOWNLOAD MSI AFTERBURNER
MSI Afterburner 2.2.0 Beta 2 download from Guru3D.com

2. Fire it up. The stock voltage should read 1.149v if i'm not wrong. Now, you'll have to navigate through settings on the right corner and check "UNLOCK VOLTAGE CONTROL"

3. Now close MSI AfterBurner(the 'X' button on the right top corner). Start it again.

4. Slide the "CORE VOLTAVE(mV)" slider from 1.149v to 1.10v first.

5. If you have installed KOMBUSTOR, use it to check for stability, I say 15 minutes should do it(why, read on).

6. Now if you've got it stable, you can go for some of the undervolts other people have achieved with loads of tuning. And that's 1.05v
READ THIS: SPCR • View topic - Radeon 6850 Undervolting Survey

7. If KOMBUSTOR shows stable at 1.05v, you are in for the last step(lucky you, got a binned card). Step it down to 1.03v(not lesser)

8. Again check stability, run some intensive games(Crysis 2?) or something like 3DMark11 if you have installed.

There you go, the undervolt should help reduce your temps at the same fan settings in the same game(at least it does for me and my HD5850).
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Since you have a Athlon II X4, you are in luck, I have the same CPU and have done some extensive undervolting on it. The X4 635 is 2.9GHz if I'm not wrong.

Hmm, 1.25v seems quite good. But I think you can hit lower. I'm able to do 1.15v on my Athlon II X4 620 2.6Ghz. You can definitely try for 1.20v(each 0.05v step down brings power consumption by about 5W, read in some tomshardware review looong back)
 
Thanks for the quite comprehensive response Comp@ddict, i appreciate it

But i have only one query

is it safe enough to run Kombustor for stress testing my GPU?

i say this 'cause Guru3d guys dumped this as a stress testing tool citing that it has the potential to harm the GPU under stress
 
is it safe enough to run Kombustor for stress testing my GPU?

i say this 'cause Guru3d guys dumped this as a stress testing tool citing that it has the potential to harm the GPU under stress
Click to expand...

well, furmark is even worse according to me. but as I said, try a game. Crysis 2 would be a great stress tool.
 
If kombuster can harm your gpu (according to you) then Furmark will BLOW it away..HAHa..Anyways, yeah! you can definitely use it to check the stability of your card..So NO WORRIEs.

BTW why are underclocking your gpu in the first place? 67 C is cool as ICE (On AIR) when it comes to GPUs these days..

And if you still think its high, then just turn on the AC xD....the temps will plunge by atlest 6-7 C.
 
I'm actually waiting for sourav to post temps for the same game and same fan speed without mods and with undervolt.

I got about 5-7C temps drop, lets see how good he does.
 
sorry guys i was late in replying

i did install the Kombustor and Afterburner

they came in a single 25mb package

Afterburner installed fine but kombustor was having trouble starting up citing some "d3dcompiler_42.dll missing error"

so it took me some time to realize that Windows 7 probably doesn't pack the latest DX version so i re-installed it from Microsoft's web installer and Kombustor runs fine now

so here's some screenies from IDLE state before i change anything

5rr.png
92m.png




now i cant seem to find the option to change the core voltage of the GPU

the option in Kombustor is "greyed out" or "Disabled"

where do i enable it?
 

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and here are screenies after 10-15 mins of Bioshock[2007] at highest settings@1600x900



now i know that the temps appear to be fine now but it peaks to 73C sometimes at day during gaming

hence my concern
 
it is this card exactly

Newegg.com - SAPPHIRE 100315L Radeon HD 6850 1GB 256-bit GDDR5 PCI Express 2.1 x16 HDCP Ready CrossFireX Support Video Card with Eyefinity

i guess its in stock settings

in the Afterburner Settings panel there are two options

"Unlock Voltage Control"

"Unlock Voltage Monitoring"

which one should i check?

also Comp@ddict what are the risks i am taking by throttling the voltage lower from default settings

i.e.

what are the risks that i am taking by Undervolting and/or Underclocking my GPU?

Okay its showing 1149 mV when i check "Unlock Voltage Control"

guess its stock card then

the Asus ones were factory undervolted

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okay i Throttled the core voltage to 1.1v in Afterburner

ran the Kombustor for 10 mins

here's the screenie

HD6850@1.1v Kombustor@10mins



GPUZ readings

GPU Temp= 76C

GPU Temp#1= 75

GPU Temp#2= 76

GPU Temp#3= 78

these are the max values after that i turned off Kombustor

Proccy was hovering around 50c-45c

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HD6850@1.05v Kombustor@8mins



GPUZ readings

GPU Temp= 75-76C

GPU Temp#1= 75

GPU Temp#2= 76

GPU Temp#3= 79

i will test it at 1.03 volts tomorrow

but i am not seeing any real world changes in temp yet
 
Dont do 1.03v yet. Fire up a game, set fan at 45%. Play the game with and without undervolt(1.05v). If there's no difference, then I'll cut my beard!

"Unlock Voltage Control"

"Unlock Voltage Monitoring"
Click to expand...

Both if you wish, 1st one for your purpose.

also Comp@ddict what are the risks i am taking by throttling the voltage lower from default settings
Click to expand...

from what I know, it's nothing. If the voltage is too low, the card will become unstable and games might crash. Then up the voltage again to stability.

But dont do 1.03v, stick to 1.05v and play some games and set a fixed fan speed i.e. like 45% while gaming, and then check difference.

(dont fix 45% for kombustor, and leave kombustor, move to games)
 
Okay sticking to 1.05V for now

no Kombustor anymore

To be honest i didn't see any change in temps between 1.149(stock) and 1.045(undervolted)

today i played Bioshock again for 2 Hours at stretch at highest settings and the temps were maxed at 70-73C at stock automatic fan speeds ambient is 40C

But my brother wants to play Crysis[2007] which should be even more resource intensive

so i was wondering if reducing the core clock from 775MHz to 700MHz and fan speed to 70% while gaming would help with temps?
 
^^

70C is just fine.

I am seeing so many threads where users are worried about GPU temperatures in the 70-80C band. Whats up..?
 
mate your temps are normal, here members have more hotter card, i would suggest you to use your card as it is :)
 
funkysourav said:
Okay sticking to 1.05V for now

no Kombustor anymore

To be honest i didn't see any change in temps between 1.149(stock) and 1.045(undervolted)

today i played Bioshock again for 2 Hours at stretch at highest settings and the temps were maxed at 70-73C at stock automatic fan speeds ambient is 40C

But my brother wants to play Crysis[2007] which should be even more resource intensive

so i was wondering if reducing the core clock from 775MHz to 700MHz and fan speed to 70% while gaming would help with temps?
Click to expand...
now I have to say, you are being very very panicky!!! Whats the warranty period of your card? (3 years?, lol fire it up, I say push the clocks upwards not downwards)
 
asingh said:
^^

70C is just fine.

I am seeing so many threads where users are worried about GPU temperatures in the 70-80C band. Whats up..?
Click to expand...
yes i guess the temps are normal and i shouldn't worry too much :)

But i am not only interested in undervolting just for the sake of necessity but for curiosity as well

I needed to see how cool i can run my rig and also to extend the working life of my hardware(albeit theoretically)

comp@ddict said:
now I have to say, you are being very very panicky!!! Whats the warranty period of your card? (3 years?, lol fire it up, I say push the clocks upwards not downwards)
Click to expand...

i intend to do the same Comp@ddict

But the Ambient temps at my place is preventing me to do so

I just played Crysis v1.2.1 on the highest settings (anti aliasing 2x)

the temps were good 70c (max 76c) didn't check the frames at 4xAA yet

so i guess its okay, no more undervolting the card

however i noticed some rare screen flickering at Bioshock, is the throttled voltage acting up? do i need to loosen the voltage?

the screen flickered for just about a sec or two yesterday when i played Bioshock for 3 Hrs
 
I just played Crysis v1.2.1 on the highest settings (anti aliasing 2x)

the temps were good 70c (max 76c) didn't check the frames at 4xAA yet
Click to expand...

great temps, i hot 70c on my card, sometimes 72c, buddy relax.. 70c is like beach in UK for gfx cards, cool, sunny, and delightful(the view :p)
 
me using 949v @core 600 nd mem 500...i use this for all the games xcept crysis 2. coz in crysis 2 fps reduces to 20..but other games get abt 35fps...btw its completely stable...
 
Guys
i undervolted my HD6850 a couple weeks back using the MSI Afterburner
the stock Voltage was 1150v which i lowered bit by bit to 1031v
and rest everything (memory, fan, core) at stock
here are some screenies from GPUz for reference

These are the stats after 1 hour of Crysis [2007] Very High settings 2xAA
attachment.php


This is the stats after an hour of idling on desktop
attachment.php


now i am facing a minor irritant
my card is stuck to 1031v at both idle and load profile
typically the card should undervolt itself to 945v @100MHz Core/150MHz Memory, when i am at desktop/not gaming
what is the problem here?
is it something to be worried about?
 
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