HD 7950 Limits? 6 pin

[wand3r3r]

What were the limits on a 6x6 pin 7950?
I just replaced the TIM on a 7950 and was playing around a little with it.

I haven't ran any tests that will really determine stability, just Heaven UIgine and 3DMark11. It goes to Afterburners max 1100/1575 (1.25v haven't tried less). I'm wondering if it pays to try go further or if it's futile with the max TDP of 6 pins x2?

3DMark11 1.05
P9350
Graphics 9940
Physics Score 7976
Combined Score 7880

What was the afterburner mod to go higher on the clocks?
Edit: I'll google it later if this card can even handle it...

 

[BallaTheFeared]

There is no hard limit on what 6+6 can provide, specifications say 75w for 6 pin, plus the pcie lane is 75 so while staying within specification you can use 225w, but as I said realistically there is no actual hard limit.

6+6 can easily draw more than 75w.


Check mark "Extend official overclocking limits", it's at the bottom of the general tab.

 

[wand3r3r]

What other tricks did you do? Was force constant voltage necessary? I remember reading about various issues but it's been over 1.5 years.

I have to update afterburner, I had some old version that allowed the 680 voltage control from before the neutering. It didn't even have that checkbox, I think it was a manual config edit at that point.

 

[ICDP]

http://forums.overclockers.co.uk/showthread.php?t=18431335

This is an excellent guide on overclocking a 79x0 card using MSI Afterburner. I have a 6+6 pin 7950 TF3 and it clocks to 1230/1750 using this guide. If you have a WF3 or XFX card it will most likely be locked voltage.

 

[Face2Face]

Like Balla said the specification of a 6 pin PEG is 75watts, but they are able to deliver more when needed. Even with a 8pin PEG you are only adding 2 grounds with the same amount of 12v leads as the 6pin and they can pull a spec of 150watts. The card's TDP limit is not going to be limited by the PEG connector, but the card's TDP.

A stock 7950 has a TDP of 200w. Add +20 power limit your are up to 240w.
The 7950 Boost has a TDP of 225w, I am not 100% sure it shares the same 240w max TDP, because this is just a bios/voltage change and nothing changed on the PCB or hard modded. A lot of Boost cards have problems with throttling at stock speeds because of there increased TDP. They need the power limit set to + 20% at stock clocks to keep from throttling. When overclocking Boost cards it helps to unofficially raise the Power limit to + 50% if they are still seeing throttling at + 20%. They usually only need + 35% or so to keep from throttling, but I don't think this actually raises the TDP much beyond the 240w limit or even at all? Not really sure..

The 7970 PCB's are desirable on 7950's because it raises the TDP to a max of 300w, which allows for higher overclocking if your chip permits. So anyway, the limitation is with the card and not the PEG connectors.

 

[spinejam]

In concurrence w/ the previous posts, 2x6pin provides plenty of juice for overclocking. Here's my Sapphire 7950 Dual-X (2L), which is 2x6pin:



Uploaded with ImageShack.us

 

[wand3r3r]

In concurrence w/ the previous posts, 2x6pin provides plenty of juice for overclocking. Here's my Sapphire 7950 Dual-X (2L), which is 2x6pin:



Uploaded with ImageShack.us

Does hyperthreading do that much (11k)? A 3570k at 4.7GHz is around 8k physics. That's a nice OC (on the 7950).

I figured out how to increase the OC limit.
I just added /xcl to the Afterburner shortcut (right click / properties / Target> "C:\Program Files (x86)\MSI Afterburner\MSIAfterburner.exe" /xcl)
Then started Afterburner where it acknowledged the change and requires a reboot. Then just delete the /xcl from the target.

 

[Durvelle27]

Does hyperthreading do that much (11k)? A 3570k at 4.7GHz is around 8k physics. That's a nice OC (on the 7950).

i would have thought a i5 that high would be around 10K. I get 8.3K @4.8GHz