Increasing 6870 overclocking potential

[bonzai_cyberninja]

Hello everybody, I've been doing some thinking about ways to increase the performance of my 2x hd 6870's, and have gone down the path of using all the usual over clocking utilities, and getting reasonable results, hitting around 1000mhz on the gpu, and 1220mhz on the memory with a modest increase on the gpu voltage, and as these card offer no voltage control on the memory side of things, sticking with the default memory voltage settings.

Whilst playing around with the cards, and reading about other people's attempts at over clocking, modifying and otherwise boosting the performance of the cards, a thought occurred to me! I remember back, a year or 2 ago, I had 2 awesome hd 4890's, that offered an incredible amount of over clocking potential, in fact, if I recall correctly, they were able to clock the memory to around the same as the 6870, and the gpu somewhere in the vicinity of the 1150-1180mhz range, and also offered a far more comprehensive array of voltage control for both gpu and memory.

This led me to wonder why an older card could have so much over clocking potential, whilst a newer card offered comparatively so little, and I came to the conclusion that this was perhaps due to the 4890's use of the voltera control chips on the 4890, that seemed to mysteriously go missing on later amd graphics solutions.

So, with this information in mind, my questions are as follows:

Would it be a feasible idea to transplant the voltera chips from my 4890's across to my 6870's?

Would it be reasonable to assume that the graphics card, and the software would be able to recognise these chips and use them accordingly?

Is there something else that I have missed in regards to the voltage control of the 6870's that would give me greater control over the cards, and therefore better over clocking?

Finally, has anyone else attempted such an undertaking, I know plenty of people have volt modded their graphics cards and had varying degrees of success with things like that, but that's not what I'm aiming for, I want greater control over my card, so I would greatly appreciate suggestions of "why not volt mod it" not being thrown into the mix please?!

That pretty much it, looking forward to your ideas!!!

 

[XacTactX]

Your 6870 has core voltage control, and my understanding is that you are using it to hit 1 GHz, so you aren't going to get any gains on the core if you did this. The memory isn't going to go much faster than 1220 MHz, and even if it did, your real performance gain (if it hit 1350 MHz for example) would be < 5%.

Now let's talk about actually doing it. The voltage regulator is an SMD part, you would need to have insanely good soldering skills to pull it off. Then you would have to see if both voltage regulators use the same interface (maybe I2S), and you would have to see that they use the same physical package, and the pins map out to the same functions. I would have to use a microscope to show you how small the chance is of all these variables working in your favor.

At the end of it all, your time, effort, $$$, etc. would be much better spent buying a new GPU.

 

[bonzai_cyberninja]

Your 6870 has core voltage control, and my understanding is that you are using it to hit 1 GHz, so you aren't going to get any gains on the core if you did this. The memory isn't going to go much faster than 1220 MHz, and even if it did, your real performance gain (if it hit 1350 MHz for example) would be < 5%.

Now let's talk about actually doing it. The voltage regulator is an SMD part, you would need to have insanely good soldering skills to pull it off. Then you would have to see if both voltage regulators use the same interface (maybe I2S), and you would have to see that they use the same physical package, and the pins map out to the same functions. I would have to use a microscope to show you how small the chance is of all these variables working in your favor.

At the end of it all, your time, effort, $$$, etc. would be much better spent buying a new GPU.

So in other words, your saying my chances are pretty much 0 at getting this idea to work, and that my idea is out the window burning in flames then?

I wasn't looking to buy another card, as ultimately the twin 6870's work very well, and deliver excellent performance in all the games I play, it was more just a hope for enabling more power, greater over clocks on my cards, especially as my gigabyte 6870OC offers no voltage control to anything, unlike my plain old gigabyte 6870 at least offers voltage control on the gpu, so I was hoping to find some way of enabling control of the second card to push them further!

 

[Black Flag]

As a previous owner of 6870's I want to mention that if you set the voltage to 1300 mV, you will be able with proper cooling to use them for 24/7 stability in 1035/1250 MHz. But you need a good cooling solution. Especially for the core and the VRM's.

 

[bonzai_cyberninja]

As a previous owner of 6870's I want to mention that if you set the voltage to 1300 mV, you will be able with proper cooling to use them for 24/7 stability in 1035/1250 MHz. But you need a good cooling solution. Especially for the core and the VRM's.

Yes indeed, I have rather nice cooling for my gpu's, in the for of the arctic cooling accelero extreme plus, a most capable cooling solution.
I am easily able to set one gpu to 1300mV and crank the core right up, however, the other gpu offers no such adjustments to voltages, hence my desire to modify it in some way!

Ideally I would like to run them both at something like 1GHz on the core, and 1.2GHz memory, as I can get that with the standard gigabyte, but not with the OC version ( I don't quite understand how you can sell a card with a mere 15MHz increase in clock speeds as OC, but there you have it ) it offers only clock speed increases!

 

[Black Flag]

6870's are stable in 970/1150 MHz without needing to change the voltage. I had two reference 6870's and one custom. All of them from Sapphire brand. And they were stable at 970/1150 MHz...