Need help overclocking 6770

[itsakjt]

Hi all,
I need help overclocking my GPU. Currently I am running my Sapphire HD 6770 at 1000 MHz and 1290 MHz memory. I set the voltage from 1.2 to 1.25 in Radeon BIOS editor. But AIDA 64 still shows that the voltage is 1.20. Although I can overclock much higher than previous. Also is there any way to increase the memory voltage of the card? The memory bandwidth is all this card lacks maybe.

 

[Aquinus]

Also is there any way to increase the memory voltage of the card? The memory bandwidth is all this card lacks maybe.

With GDDR5? I doubt it. Honestly I would leave the memory alone and focus on the core clock. Instead of flashing the BIOS on the GPU (which is usually never a good idea unless you have to,) have you tried using MSI Afterburner? It is possible that the VRM might not be accessible, so even a BIOS flash wouldn't change that.

What does GPU-Z say that your GPU voltage is?

 

[itsakjt]

GPU Z shows voltage is 1.20V at load and 0.95V idle. And yes it is GDDR5. Default 1200 MHz memory clock and 850 MHz GPU. I have tried MSI Afterburner, Sapphire TriXX but in vain :-( Any volt mods that I can do?

 

[Aquinus]

GPU Z shows voltage is 1.20V at load and 0.95V idle. And yes it is GDDR5. Default 1200 MHz memory clock and 850 MHz GPU. I have tried MSI Afterburner, Sapphire TriXX but in vain :-( Any volt mods that I can do?

Your memory bandwidth should be plenty, I wouldn't touch it as I said before.

It sounds like you don't have control of the VRMs through the I2C bus. There may be physical voltage mods you could do, but unless you have experience soldering and doing these kinds of mods, I wouldn't even consider it. If you really need more video power, save up some money for something better that has the control and ability to overclock well. Also 850Mhz to 1Ghz without touching the voltage is pretty good. I wouldn't go ruining the card just to try and get more because there is a good chance you'll end up with a dead card.

 

[itsakjt]

Ok Anyways, 1000 MHz is unstable. I am stable at 980 MHz. I was just wondering about the memory bandwidth because say if I increase the memory clock from 1290 to just 1320, I get 2-3 FPS more in games.

 

[Tatty_Two]

In any case, a further memory overclock would only bring a very small gain. I too don't know of any programme that lets us adjust memory voltage through software, do they all even have a programmable controller for memory?

 

[itsakjt]

Yes I think they have got a separate VRM for memory. One thing I cannot figure out. It is that if I can't change the GPU voltage using the BIOS, what's the use of specifying it in the BIOS? I think the power control IC is microprogrammed in some way or the other. Now I am running it at 980 MHz, 1310 MHz. BTW, this is the card- http://www.sapphiretech.com/presentation/product/?cid=1&gid=3&sgid=1073&pid=1190&psn=&lid=1&leg=0

 

[Tatty_Two]

Yes I think they have got a separate VRM for memory. One thing I cannot figure out. It is that if I can't change the GPU voltage using the BIOS, what's the use of specifying it in the BIOS? I think the power control IC is microprogrammed in some way or the other. Now I am running it at 980 MHz, 1310 MHz. BTW, this is the card- http://www.sapphiretech.com/presentation/product/?cid=1&gid=3&sgid=1073&pid=1190&psn=&lid=1&leg=0

I have no doubt they have a seperate VRM but thats not a programmable controller, without one it cannot be controlled lol. So if no controller, all the fiddling in the world won't change anything...... not sure if the one controller feeds both GPU and memory or what though.

As far as the Bios goes, if the controller is not programmable it won't work although RBE may well still offer the option, which method are you using to change the volts, could you post a screenie of RBE and indicate which method you are using because if my memory serves me correctly there are 2 visual methods but only one works.

 

[itsakjt]

This one.


Uploaded with ImageShack.us

 

[Tatty_Two]

I'll have to take a look when I get home from work, image is blocked on work computer.... I will get back to you in a couple of hours!

 

[itsakjt]

Ok.

 

[Tatty_Two]

No I don't think you can, you do not have a programmable voltage controller, your voltage registers are dimmed out and that's where you would successfully do it.

 

[itsakjt]

Ok. Better to live with keeping it as it is then.

 

[Hellraiser1981]

Sounds like you would need to do a hardware voltmod for more. What is the PWM controller on the card? If the FB is connected directly and the IC does not support offset, then a manual VID may be the only option, not recommended.

 

[itsakjt]

Need to take a look. No idea what chip is there. Anyways, better not to do it for the safety of the card.

 

[Hellraiser1981]

Need to take a look. No idea what chip is there. Anyways, better not to do it for the safety of the card.

Well the "safety" depends on the PWM controller and options. If you have good cooling 1GHz GPU is waiting....

 

[Jstn7477]

Considering that a Radeon 5770/6770 uses 128bit GDDR5 @ 1250MHz with no issues, don't bother with the RAM.

EDIT: I'm tired, thought you had a 6670 lol. My 5770 did 960/1300 on stock volts and only got to 1000/1300 max so your overclock is fine. Modded mine to 960/1300 and it still works great after 2.5 years even with its new owner.

 

[Aquinus]

Well the "safety" depends on the PWM controller and options.

No, the "safety" depends on the user's experience soldering and doing physical mods to hardware. No experience makes this that much more dangerous, which is why I pushed him away from it. It's not typically a good idea IMHO unless you know what you're doing. If you have to ask someone, you shouldn't do it.

 

[Tatty_Two]

No, the "safety" depends on the user's experience soldering and doing physical mods to hardware. No experience makes this that much more dangerous, which is why I pushed him away from it. It's not typically a good idea IMHO unless you know what you're doing. If you have to ask someone, you shouldn't do it.

Agreed..... 1290mhz memory speed is much better than 0mhz memory speed!

 

[itsakjt]

Yeah right. I can't do volt mods with risk now as I am a student and don't earn on my own, it is not possible for me to get another card now. Though I have experience in soldering but still I am afraid that I may kill the card. Anyways, I would have been much happier if Sapphire unlocked the voltage control of the card. The cooler is excellent. Full copper base with 2 heatpipes. Temps always stay around 70 degree C even on Furmark.

 

[dyingdreams]

I used to have a Sapphire 5750, which is the same exact thing as a 6750, which is almost the same thing as a 6770 but with less cores and lower clocks. Anyway, I was able to max out the memory clock (1430 in Catalyst, up from 1150) with no crashing or artifacts, while I was only able to get the core clock up to 840-850 from 750 before I would get driver crashes. Your card seems to favor the exact opposite, have you tried raising the memory clocks higher? I too would notice a considerable increase in fps from rising the memory clock, especially while playing WoW in crowded areas like Org. One thing I did to my card was to get some cheap small heatsinks to place on the ram chips on the top side of the card, I think the chips on the bottom were inaccessible due to the stock heatsink.

 

[itsakjt]

Yeah that's my point too. Overclocking the memory increases performance significantly. I can get the memory clock stable at maximum 1320 MHz but I selected 1300 to leave some space.

 

[swjpjj]

My Asus 5770 OC980/1300Mhz. Graphics memory temperature is very high, which is what you need to pay attention.

 

[itsakjt]

Yeah. I know. BTW, your overclock is same as mine.

 

[johnslash]

Try this program and see if you can increase or decrease your volt.
http://dlcdnet.asus.com/pub/ASUS/vga/app/GPUTweak_2_2_9_9.zip

Let me know, and, could you upload your edited bios here ?

Thanks.