# [0.5.6] 0.000 VDDC on HD 6950



## FM (Dec 9, 2011)

Over the summer I bought a new PC, including the Dirt 3 version of Sapphire's HD 6950. It worked out fairly well, especially after a shader unlock, but I was never able to push it quite where I was comfortable with. Sapphire's Trixx utility seemed to produce poor overclocks for whatever reason, so I decided to use MSI Afterburner.

However, after a certain point, GPU-Z, which I was using to monitor things, refused to report voltage. And MSI Afterburner refused to allow me to see or change voltage. I could still change voltage in Trixx, but without monitoring tools I had little method of correction, and as stated it seemed unstable anyway. This might be related to a driver issue, as I believe it coincided with a Catalyst update...but I don't know for sure.

I have tried a few basic troubleshooting methods. I reflashed to the stock BIOS. I performed a clean install of Catalyst. I made extra sure that it really was the stock BIOS I flashed. Unfortunately, nothing doing. I haven't tried reseating the card, updating the motherboard BIOS, or switching to the secondary video BIOS yet, however.

I'm hoping it is an issue that can be solved with a registry edit or something I've overlooked! I'd hate to have to try to send the card back to Sapphire; I don't think they'd take it back.


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## Raydeon (Dec 13, 2011)

dirt 3 model and variant are not supported, ask wiz to add it, he programs trixx for sapphire, and codes gpu-z too, might be on the "To-Do list".

Oh... and your only going to get more than 1.18 volts max on the dirt 3 and variant HD6950 via trixx.

Variant = dual fan, dual bios, vapor chamber style cooler, blue pcb.


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## FM (Dec 13, 2011)

If it's not supported, that's one thing, but it _used_ to work. And now it doesn't. Strangely, SpeedFan _does_ seem to read the voltage...

As for Trixx, I can't get much of an overclock at all out of it. 880/1375 is the best I get, and that at 1.165v! Compared to what other people are able to get, it seems awfully substandard.


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## cadaveca (Dec 13, 2011)

The ATI 69xx series cards are subject to power consumption limits that will affect how each card clocks individually.

I have one card that won't budge over 880/1375, and under default votlage, it would only get 840Mhz/1275 Mhz stable. The best I could get was 925 mHz with a severe overvolt.

Then, I put the card under water, and got 900 MHz, no problem, on stock volts.


Now, I've increased the power slider in CCC to 25%, and I can get 880/1375, on stock volts, which wasn't even remotely possible before.

Of course, there's this RacerX mod available her on the forums, and recently he released info o nhow to adjsut those power maximums. I suggest you follow the directions, and give it a go, increase the power limit in CCC, and see if your card doesn't clock way better, even on stock voltage.


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## FM (Dec 13, 2011)

I'll try it out in a bit. I've already unlocked my clocks with RacerX, but haven't modded power limits up. I have done so before, but it doesn't seem to cooperate well with Trixx...

And where's the info on modding PowerTune limits up?

EDIT: Nothing doing, so far anyway. 20% didn't help; I still had driver crashes, game freezes, and a hardlock. That mod might be quite helpful...and I was only using CCC at the time.


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## cadaveca (Dec 13, 2011)

it ups the limit form 20% to 50%. it's at the end of the "raise overdrive limits" thread.


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## FM (Dec 13, 2011)

Well, I tried that, and it looked promising until I got a grey screen and hardlock at both 25% and 30%. I'm afraid of pushing it any higher than that.

I guess all I can do now is try to fiddle with Trixx again and hope CCC remembers the PowerTune settings. I _think_ Trixx cooperates with the setting, but the setting might have returned to default at some point. Of course, Trixx seems to introduce instability and it doesn't remember to reapply custom fan profiles on startup, so there's other problems...thanks for your help so far.


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