Higher power limit, better undervolts?

Discussion in 'Videocards - AMD Radeon' started by reslore, Dec 6, 2021.

  1. reslore

    reslore Active Member

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    GPU:
    ASUS Vega 64
    Okay, I've been experimenting with NimeZ custom 21.12.1 modded AMD Drivers. I was really excited about trying SAM on my Vega, then I found out it has an unlocked power limit.

    Instead of a limit of 20% for my Vega 64 for instance, it can go to 50. I have a finely tuned undervolt that I use, with 1037 mv instead of 1200 stock. Normally I use a 3% power limit on it.

    Well, I keep the same settings and start cranking the power limit up, instead of ~228 watts max, I get it to 240, 250, 260 and so on.

    So, I have this undervolt of mine pulling more power than ever stock, I benchmark it, same results. Oh, there can still be potential I thought, so I start upping the max clock.

    I managed to raise it from 1650 max to 1690 max clockrate in minutes just by raising the power limit from 3 to 40%.

    Max wattage is still under 260 watts, well under the power limit in BIOS.

    Here's two benchmarks, first my old PB with this Undervolt then what I achieved in minutes beating it.

    I know the power limit is set very conservatively in new cards, maybe some other enthusiasts want to experiment, I know I will be. I think there's great potential here.

    Top is old Personal Best on my undervolt, bottom is 40% power limit:

    PWRLMT.PNG
     
    Last edited: Dec 6, 2021
    OnnA likes this.
  2. reslore

    reslore Active Member

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    GPU:
    ASUS Vega 64
    Follow up post after playing around with my undervolt / OC

    Here's my new 100% tested and * stable * settings and a firestrike result, these settings max out at about 252 watts in both cases, stock limit on bios is 260 watts for reference.

    This undervolt is performing stable at top 1% levels using less wattage than the card bought STOCK :eek:

    All other settings and conditions the SAME, except power limit.
    Keep in mind it is stable in both conditions as well.

    Power limit +40% :

    ResultA.PNG

    Power limit +3% :

    ResultB.PNG

    I thought this was some tin foil hat stuff but it really seems to help. This is complete A to B testing with the only difference being set powerlimit.

    Does the increased limit somehow increase transient response? o_O I'm no electrical engineer.

    Just wanted to share my findings, still trying to wrap my head around this if anyone has something to add :D
     
    Last edited: Dec 6, 2021
  3. Mufflore

    Mufflore Ancient Guru

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    GPU:
    Aorus 3090 Xtreme
    The power change from 3% to 40% increased your graphics score 0.4%, the best score change of all those posted.
    Theres nothing to work out because there is very little change, except maybe why there is so little change!
    You wont notice a difference when gaming.
     

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