How well does the 7700HQ undervolt?

Discussion in 'Hardware Components and Aftermarket Upgrades' started by Ickarius, Jan 22, 2017.

  1. D2 Ultima

    D2 Ultima Livestreaming Master

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    MSI and Clevo owners on this forum are generally undervolting nuts. ASUS to a lesser extent. Most of them will be looking to undervolt. You just need to wait for the active/helpful ones to get some. If you find any of them who will give you their readouts, then great. But like the number of responders in this thread, the number of helpful/savvy people who already have one is low.

    Reviewers will almmost never undervolt. Unless HTWingnut (or myself) is doing the reviewing, at least, for the most part. But 0.965v for 3.4GHz is extremely little... I don't imagine it would have so much room. Idling at such a low voltage, however, is normal. I just watched my CPU idle in Throttlestop and it hit 0.6312v at a low point, so... Kaby Lake's idle voltage isn't impressive. When a CPU is clocked low, voltage almost always remains really low (from intel anyway).
     
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  2. AndiiiHD

    AndiiiHD Notebook Consultant

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    mine 7700HQ is working fine with an undervolt of -150mV on CPU cache and core with speedshift activated. In Prime95 the temperature now does stay in the low 80's under full loads. You can find my idle and under load (prime95) Voltage attached .

    i did not check any lower settings but i will do this if i find some time for testing. I only had tried to apply -200 instead of going little steps but it freezes immediateley. ;-)
     

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  3. cracken

    cracken Notebook Enthusiast

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    Prime 95 did fail on one of the cores at -170mV after 24 minutes. Also graphical anomalies while outputting to 4k TV despite not downvolting the iGPU yet and running just on the dGPU. I output to my 4k 40in TV as my main monitor when I'm not using it as a laptop so this was a weird bug but is unacceptable.

    Prime 95 failed at 17 mins on -160mV on one of the cores. Same graphical anomalies above, when i move windows it leaves a shadow of itself in effect. Opening other apps in full screen and what not to try to clear it doesn't fix it.

    At -150mV while prime 95 doesn't fail or show errors for 44 minutes during the test, but it froze my computer when i stopped prime 95 so i could go to sleep. There was also a graphical glitch while clicking around in TS but prime 95 didnt show errors either. Because of that. I don't believe -150mV is stable.

    -130mV CPU Core and Cache and was stable for 3 hours 3 minutes. Another test showed it stable for 2 hours on prime 95. Temps are reaching 85C max but usually hover around mid to high 70s. I would like to note that no game can push the CPU temps past 51C including Witcher 3, For Honor Beta, and GTA 5.

    Its exhausting to also test the effects of disabling turbo boost and clamping the Package Power Limits to a certain watt independently, and seeing the effects on battery life. So i'm just going to use the laptop in normal operation with turbo off and will keep lowering the package power until i see noticeable lag before I do a battery drain test. Will take a week or two & will update this post.

    Updates: I got graphical anomalies bring back my computer from sleep while undervolted at -130. This is with discrete graphics mode only, and connected via HDMI to a 4k 40in TV/monitor. Thought it was something else but turning TS off completely solves the problem. Lowering voltage to -110mV and will see.

    Update: Computer automatically restarts when coming out from sleep after not using computer 1-2 hours at -110mV. Reducing it to -100mV and will see if that's stable. If i put my computer into sleep manually and then wake it up, its fine. If the computer falls asleep for a short period of time it also wakes up fine. But if it falls asleep for more than 1.5 to 2 hours, it automatically restarts. Very troublesome for critical work. Anyone else having issues coming out of a long sleep?

    Update: -100mV to CPU and Cache seems to be stable coming out from sleep. That plus disabling turbo, -40mV to iGPU, and clamping the Package Power Limits to 15 watts allowed me to get a battery life of 4 hours before hitting 7%! Before the laptop only got 3 hours 41 minutes before hitting 7% battery on iGPU and 2 hr 50 mins if on dGPU. Despite clamping the Package Power Limits so low, I did not notice any slowdowns and the laptop still feels a lot faster compared to my Dell XPS 9350 with a Intel i5-6200U. I will continue to try lowering the iGPU voltage and clamping the Package Power Limits to see if i can get further battery life improvements.
     
    Last edited: Feb 20, 2017
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  4. Blatcher2

    Blatcher2 Newbie

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    Currently testing -150mv on CPU core and cache. Using throttle stop and hitting 3.4 GHz on all 4 cores. 60 min stable on AIDA64. Integrated graphics at -125mv and 30 min stable in Unigine Heaven.

    Voltage:
    Vid max of .957v (3.5GHz on all 4 Cores)
    VID min of .558v (897 MHz on all 4 Cores)

    On Desktop with no programs open idles between 1.3 and 1.4 GHz at .6v

    Testing done on an XPS 15 9560 (FHD with 97wh battery)

    Will do a 6+ hour Prime95 run tonight.

    Update: Stable after 12 hours with a max package temp of 84C.
     
    Last edited: Feb 18, 2017
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  5. vas

    vas Notebook Consultant

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    You are right about 150mV. Actually 150mV isn't much when you run full throttle - this is less than 15% decrease of the normal processor voltage at that speed. But look at lowest energy modes when processor itself run as little as ~650mV and you undervolt it even more (up to 500mV) - that's relatively tooooo large decrease (more than 20%) and may cause transistors just not work as expected and triggers does not trigger .... (also 500mV itself on the edge when logical units still works ...)
    So assuming:
    1) doing undervolt - take into account lowest possible power mode as well as highest.
    2) you can increase undervolt by some number if you limit processor power saving capabilities (for example disable FID less than 20) - you can run colder at high speed but not able to benefit from low power modes

    BTW:
    Throttle Stop 8.4 on my XPS 15 9560 i7-7700hq
    CPU/CACHE: -135mV
    GPU: -60mV
     
  6. vas

    vas Notebook Consultant

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    You missed one very critical stability test:
    Test your CPU at MAX FID by launching just one prime95 threads (you can launch 2 or even 3 if you configure processor to run at 3.8GHz)
    As you mentioned - you tested it at 3.5 GHz which is relatively low to 3.8 GHz
     
  7. Blatcher2

    Blatcher2 Newbie

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    I've back off to -120mV on the CPU and its been running well. I might need to raise the voltage some more to increase stability. Last week, I had a BSOD after quiting csgo directly out of a deathmatch. I might just do -100mV on the CPU and GPU to make it rock solid. Temperatures aren't a huge problem since I also re pasted and padded.
     
    Last edited: Apr 27, 2017
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  8. vas

    vas Notebook Consultant

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    Good to hear you've found stable undervolt for you..
    I stopped at -125... no BSODs for ~1 month.
    Also enabled SST for better responsiveness - PC is fast and stable at the moment and able to run over nine hours on battery (I have 4k display ... if I would have FHD I'd probably get even better battery life). Thanks to ThrottleStop developer (I use this piece of software since i7-820QM released) and those people who made research on how to permanently enable SST.
     
  9. Blatcher2

    Blatcher2 Newbie

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    I've only heard good things about speed step. Is throttle stop the best method to activate it permanently? Also how does turbo @3.8Ghz across all cores affect battery life? I was on a long road trip and got 12.5 hours of battery life watching movies using VLC player.
     
    Last edited: Apr 28, 2017
  10. Sebixy

    Sebixy Newbie

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    I have undervolted my dell xps 15 with i7 7700hq 150millivolt and it seems stable till now. Now max voltage is 0.9V and temperatures have dropped 12 C from 79 to 67 degrees. Total power consumption under stress has dropped from 33 to 23Watts. I will have to wait and do further tests to tell you if this undervolt is stable, 155 millivolts resulted in sistem freezing immediatly but no blue skreens.
     
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