AMD Powertune or "Power Li" lets talk about my issues with it.

[Stu @ MSD]

Hi Guys,
I always thought that powertune allowed a higher "Overshoot" before the clock was throttled and as suich, I have always slid it to +20% and forgotten about it.
However - I have been pushing my OC's a lot more recently and have got round to experimenting with this and found it actually makes things WORSE not better... and thats on benches like 3Dmark Fire Strike, Catzilla, Heaven 3.0 etc.
I realise this may be an anomaly with my system, or even an anomoly with the 13.2 beta 5 drivers on my trifire system, so in an effort to figure out why this may be, I spent all of last night playing with OCCT on 5 min, 2gig runs on level 7 @ 1920x1080 with error checking enabled and I was very surprised to learn that, I ALWAYS get more errors with Powertune higher than zero and find the only way to get an error free run above 1150mhz is to set it to zero and adjust the CPU voltage instead.
Example only... not exact figures but certainly representative:

• Core 1150
  
• Volts 1.150v
  
• P-tune (Power li) 0%
  
• Error free run over 5 mins.

---------------------

• Core 1150
  
• Volts 1.150v
  
• P-tune (Power li) 20%
  
• 25000 Errors over the 5 mins run.

--------------------------

• Core 1150
  
• Volts 1.200v
  
• P-tune (Power li) 0%
  
• Error free run over 5 mins.

In all runs I monitor volts and core speeds with GPU-z to ensure no overshoots or throttles and the results are always the same, less FPS and more errors. Can anyone please try to explain why this is? Am I just bloody using it wrong?

For reference:

• Cpu = 3770K @ 4.7ghz
  
• Maximus IV Extreme-Z
  
• 3x Sapphire 7970HD's
  
• Sapphire Trixx 4.4.0 modded for mem voltage adjustments

 

[Orcvader]

Is the memory overclocked as well? Usually when you start to get a lower score it's due to errors in the memory, which is usually corrected by the error correcting code.

Another possibility is that the overclock on the core is actually unstable, and you don't see it with the 0% powertune as it gets throttled back before it's properly stressed. So maybe go back down to 1100mhz and see if the problem occurs there.

 

[Stu @ MSD]

Is the memory overclocked as well? Usually when you start to get a lower score it's due to errors in the memory, which is usually corrected by the error correcting code.

Another possibility is that the overclock on the core is actually unstable, and you don't see it with the 0% powertune as it gets throttled back before it's properly stressed. So maybe go back down to 1100mhz and see if the problem occurs there.

Hi,
No, I have kept ram at standard for these tests as its hard to tell if ECC is active on the Tahiti so I use pure FPS for that.

Ref stability - sure, agree with that, however, its not throttling clocks at any stage ever according to GPU-Z.

To elaborate further, these cards will all run 1250 without errors, but ONLY if I leave powertune at 0%.
If I increase it, any speed I try produces errors.