How can I push it further?

[Forde3654Eire]

Hey all,

Alright I've successfully managed to overclock my Sapphire 6850 to 850Mhz Core Clock and 1075Mhz Memory Clock. A 1/2 hour stability test with the mentioned values on Furmark with Xtreme Burn-in went by smoothly.

I could push the memory clock further, but this resulted in no more FPS gain in Furmark... I figured out the Core Clock needs to be increased. For an overclocked card, the temps are quite nice. No higher than 59 C on Battlefield 3, maxed out at 1080p.

Now I'm using MSI Afterburner, so the cap is set to 850Mhz for the Core Clock... from the reviews I read, the 6850 is capable of achieving 890Mhz on stock voltage. I tried unlocking the "Unoffical Overclocking", however by simply doing that, I start to see my screen flickering weirdly... undo changes for "Unofficial Overclocking" and everything is back to normal.

Was it a mistake that I did somewhere back there? Did I not do the unlocking properly which resulted in my screen flickering? If I have to look at other software, what would you recommend?

 

[HugoStiglitz]

every video card and cpu will overclock differently. some better than others. what is you ASIC score in GPUz? this will give an indication of how far you can push it on air cooling

 

[Forde3654Eire]

Hi, GPU-Z simply gives me a statement saying "ASIC quality reading not supported on this card"

Is Sapphire Trixx worth giving it a shot? I only tried MSI Afterburner, never worked with Trixx before.

 

[PoplicoMan]

Its all in the GPU. If your card has no headroom then it could just be the unlucky dud, however give trixx a try. I dont see why afterburner wouldnt perform, just a little suprised

 

[Forde3654Eire]

Its all in the GPU. If your card has no headroom then it could just be the unlucky dud, however give trixx a try. I dont see why afterburner wouldnt perform, just a little suprised

You didn't get it. The slider for Core Clock in MSI Afterburner only goes up to 850 Mhz. If I try to just unlock unofficial overclocking,
my screen goes hay-wire if I do any changes at all in MSI Afterburner. It must be a software glitch... that's why I'm looking at Sapphire Trixx.

Also, I currently have the 12.10 drivers for my 6850... would I benefit from the 12.11 drivers? Or are these specifically aimed at the 7xxx series?

I just need 2 -3 more FPS gain to remain above 30 FPS in Battlefield 3, maxed out at 1080p. I'm wondering if flashing my BIOS to the latest version would help?

EDIT: Oh and what about flashing my card to mimic the settings of a 6870? I understand the whole 6950 / 6970 idea, and that in their case, more shaders get unlocked... however, that is not the case with the 6850 / 6870. What is does give me however is a stable overclock with stable voltage increase, all done automatically for me... is that right?

So how can I flash my card? Where can I get the 6870 BIOS?

 

[Forde3654Eire]

Hey guys,

First off, sorry for posting too much about this topic, but I just want to be extra sure I am doing my overclocking properly for my Sapphire 6850. I know of a few people who are so careless with OC'ing, they simply max out their Core Clock and Memory Clock and start playing...

As of now, I have successfully patched CCC to bypass the stock Core Clock and Memory Clock limits. I found the information through many threads, here is an example of a re-post:

http://forums.anandtech.com/showthread.php?t=2263110

Currently maintaining 890Mhz Core Clock and 1090Mhz on stock voltage. I am using these settings according to an overclocking review by Hardware Canucks:

http://www.hardwarecanucks.com/forum/hardware-canucks-reviews/37499-hd-6870-hd-6850-vs-gtx-460-1gb-overclocking-study-3.html

I've fired up a 15 minute stability test using Furmark at 1920x1080. Nothing out of the ordinary in these 15 minutes... just the big fuzzy donut going round and round...

Am I missing anything? I mean how obvious are artifacts? Are they very hard to spot or are they very clear? Shouldn't I be running into problems at this stage? Am I doing the stability test wrongly? How long should I run the test for? Once again, on Furmark, its "Stability test", "Fullscreen", "1920x1080"

 

[Dude496]

Artifacts are quite noticable. Once you start pushing your card too hard, you will see wierd pixel flickering (probably wrong term, but that is the best I can describe it). On my card, when I push it too hard I start seeing blobs of colors, sometimes yellow sometimes green sometimes pink, it's just random. Once you push your card past its limits, windows will crash or the program will crash and typically give you an error about the video driver stopped responding.

If you take that a step further and push the voltage too far, the computer will most likely just shut down and most likely you will let the magic smoke out of the GPU and possibly motherboard....in other words, you'll fry your GPU if you push the voltage too far.

Furmark is great at stress testing GPUs for temperature checks. I would also recommend using Unique Heaven 3.0. The nice thing about heaven is that the freeware version of the program allows you to loop the program for as long as you want. 3DMark11 is also great at stressing the GPU to check for artifacting, but the only problem is that the freeware version does not allow looping to continue running the program...it will only allow you to do one full run, then it will quit and give you the results.

 

[Dude496]

Oh btw, doing the unofficial mode on Afterburner is notorious for causing screen flickering...it shouldnt happen while you are playing a game, but when ever you are switching programs or loading programs, it will flicker...it is rather annoying. The only time I use Afterburner is when I want to disable powerplay to do some testing. Otherwise, I prefer to use the /xcl method...I have yet to have any problems with screen flickering using that method.

 

[Forde3654Eire]

Oh btw, doing the unofficial mode on Afterburner is notorious for causing screen flickering...it shouldnt happen while you are playing a game, but when ever you are switching programs or loading programs, it will flicker...it is rather annoying. The only time I use Afterburner is when I want to disable powerplay to do some testing. Otherwise, I prefer to use the /xcl method...I have yet to have any problems with screen flickering using that method.

Hey thanks for the reply. I've just finished running another 1/2 hour test on Furmark on Xtreme Burn-in and some Battlefield 3. No artifacts whatsoever, all seems good. Battlefield 3 on ultra settings, 1080p... and this is a 6850 running off an i3-2100, rarely any dips below 30 FPS!