CPU 45W TDP Limit

Discussion in 'Hardware Components and Aftermarket Upgrades' started by Danishblunt, Nov 21, 2017.

  1. villahed94

    villahed94 Notebook Guru

    Reputations:
    5
    Messages:
    53
    Likes Received:
    28
    Trophy Points:
    26
    Technically it's a microcode downgrade. Stock Haswell silicon has a bug where it ignores fused multiplier limits and allows things like this to happen on microcodes <= 0x02.
    uCode hack.png
    woot no tdp.png

    However there are some major caveats:
    BGA i7s rarely honor TDP limit settings, almost always reverting to fused TDP values. Powercut is a godsend to this...
    As expected running the processor like this makes it really hot, and as a result my actual "daily" multis are 44/44/41/41.
    However for longer load sessions (like some intensive games, video rendering,electronics simulation) I need to drop the multi to 38x or else I'll run into PROCHOT.
    This is on a Lenovo Y50, and using Conductonaut.

    I have recently acquired a Precision M4700 for a decent price ($250-ish). It originally came with an i7-3720QM, which while decent, it lacked the horsepower I need.
    Therefore when I saw a 3940XM for a low price ($150), I grabbed it and replaced the original processor.
    Both processors did allow for TDP limits to be exceeded, will post pics later.
     
    hmscott and Vasudev like this.
  2. yrekabakery

    yrekabakery Notebook Consultant

    Reputations:
    74
    Messages:
    270
    Likes Received:
    246
    Trophy Points:
    56
    I'm not using the bugged early microcode that lets you increase multiplier beyond stock limits:

    [​IMG]

    Yeah CPU temps are fine when gaming (60-70C) or encoding long videos (80C).
     
  3. psil0

    psil0 Newbie

    Reputations:
    0
    Messages:
    5
    Likes Received:
    0
    Trophy Points:
    5
    Hi guys Im having Power limit throttle issues and maybe you guys can help. It happens when TDP package passes the limits that are locked. I want to unlock them but my BIOS is super simple and a can tweak almost nothing. Using HWinfo32 shows:

    CPU Thermal Design Power (TDP): 47.0 W
    CPU Thermal Design Current (TDC): 85.0 A
    CPU Power Limits (Max): Power = Unlimited, Time = Unlimited
    CPU Power Limit 1 - Long Duration: Power = 47.00 W, Time = 28.00 sec [Locked]
    CPU Power Limit 2 - Short Duration: Power = 58.75 W, Time = 2.44 ms [Locked]

    So i can set the power limits to an unlimited value, but it seems the manufacturer locked the limits.
    How can i unlock them??!!!

    Thanks,

    I have a clevo n170sd:
    i7-4720HQ
    GTX960M
    8GB DDR3 1600mhz
    windows 10 pro
    AC 120W
     
Loading...

Share This Page