Early results, no thermal throttling on i9 iMacs

Discussion in 'iMac' started by jonatious, Mar 29, 2019.

  1. jonatious macrumors member

    jonatious

    Joined:
    Sep 29, 2016
    #1
    Surprisingly, there is no thermal throttling on the new i9 iMacs :)



     
  2. slayerizer macrumors 6502a

    Joined:
    Nov 9, 2012
    #2
    You mean that the million people that complained about it without having one were wrong? :rolleyes:
     
  3. jinnyman macrumors regular

    Joined:
    Sep 2, 2011
    Location:
    Lincolnshire, IL
    #3
    Based on the second video, continuous load makes CPU clocks at around 3.7~3.8.
    My custom PC i9-9900k with air cooling (NH-D15) runs continuous 100% load at 4.7. (no overclocking)
    No wonder it's able to maintain higher than base, because it's only several hundred above the base clock speed.
     
  4. kaintxu macrumors regular

    Joined:
    Jul 9, 2018
    #4
    Well based on the first video, with the GPU stress test it seem to get quite hot. Maybe not enough to thermal throttle, but fan ramps up hard. You can even hear it in the video.
     
  5. Rockadile macrumors 6502

    Joined:
    Jun 11, 2012
    #5
    So far, so good. Looking forward to Max's further testing.
    --- Post Merged, Mar 29, 2019 ---
    Snarky comment is snarky :rolleyes:
     
  6. MandiMac macrumors 6502a

    Joined:
    Feb 25, 2012
    #6
    Well, everything above the base clock is technically automatic overclocking. Throttling would be the process of being under the base clock. Not reaching the highest Turbo Boost level is not throttling. Case closed.
     
  7. BigBoy2018 macrumors 6502a

    BigBoy2018

    Joined:
    Oct 23, 2018
    #7
    This is why my preference is to get the processor with the higher base clock speed and then use something like turbo boost switcher to turn off turbo boost when I'm doing any long video render or export.

    With turbo boost on, the fans run up, but I've discovered these long renders don't actually take any less time.

    With turbo boost disabled, the machine stays quieter and cooler and stays at the 3.8ghz clock speed throughout.

    To me, turbo boost is a little tweak that helps in very brief actions, and something that basically 'tricks' Geekbench and makes the processor seem faster, but for any extended use, it's the base clock speed that is going to be what you need to key in on.
     
  8. gusping macrumors 6502a

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    Mar 12, 2012
    Location:
    London, UK
    #8
    Off topic, but is the NH-D15 sufficient to keep the 9900k cool while gaming etc? Very impressive if so.
     
  9. jinnyman macrumors regular

    Joined:
    Sep 2, 2011
    Location:
    Lincolnshire, IL
    #9
    Yup. I haven't overclocked the i9 yet so it's running at 4.7 all core turbo. During the heavy gaming session (Apex Legend for example), the temp reaches maximum of 82~3 deg celsius, and usually at mid 70s. I've also made sure the continuous air flow is maintained from the front of case to back though.
     
  10. kaintxu macrumors regular

    Joined:
    Jul 9, 2018
    #10
    Is Apex Legend very demanding. I wanted to try it once I got my new iMac. Do you think it will run?
     
  11. Kaelis macrumors newbie

    Kaelis

    Joined:
    Mar 28, 2019
    #11
    Apex should run alright in 1440p with a RX580, if that’s what you got.
     
  12. kaintxu macrumors regular

    Joined:
    Jul 9, 2018
    #12
    I was thinking more on a i5 with a vega 48?
     
  13. jinnyman macrumors regular

    Joined:
    Sep 2, 2011
    Location:
    Lincolnshire, IL
    #13
    I run the game at 4k UHD resolution with max setting. You won't be able to run it at 5k of course, but on bootcamp with WQHD or something, you should be able to run pretty well with option adjusted for better performance.
     
  14. MandiMac macrumors 6502a

    Joined:
    Feb 25, 2012
    #14
    Will do.
     
  15. Kaelis macrumors newbie

    Kaelis

    Joined:
    Mar 28, 2019
    #15
    Apex runs at 52.4FPS average in 1440p/High settings on the RX580 (source gamernexus). The Vega 48 should be plenty fine for 1440p/60FPS in High/Ultra !
     
  16. kaintxu macrumors regular

    Joined:
    Jul 9, 2018
    #16
    my current iMac is not 5k, so never used one.

    Is it better to run game on 4K or 1440p which is native to the 5k?
    --- Post Merged, Mar 31, 2019 ---
    Will it be the same with the 9600K as with the 9900K if with a vega?
     
  17. MacRS4 macrumors regular

    Joined:
    Aug 18, 2010
    Location:
    London, UK
    #17
    I left my i9 maxed out today for a good few hours, never dropped below 3.6Ghz clock speed - unlike my i9 macbook pro *insert annoyed face here*.

    The iMac is also a lot quieter than my iMac Pro, which surprised me a bit.
     
  18. Bohemien macrumors regular

    Bohemien

    Joined:
    Mar 28, 2019
    Location:
    Germany
    #18
    Which graphics card do you have?
     
  19. MacRS4 macrumors regular

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    Aug 18, 2010
    Location:
    London, UK
  20. smetvid macrumors 6502

    Joined:
    Nov 1, 2009
    #20
    Which is still not throttling. It just doesn’t make use of turbo boost as much as your custom PC. I’m not really concerned with what a larger custom tower PC can do with a CPU. I’m more concerned will how it compares to other Macs.
     
  21. jinnyman macrumors regular

    Joined:
    Sep 2, 2011
    Location:
    Lincolnshire, IL
    #21
    I agree that it's not throttling by anymeans. But it nevertheless show less performance than perceived from naming though.
    As I stated in other thread, I'm content with iMac's limited tdp i9 as iMac is meant to be silent work horse AIO. Apple could've done better by chaging cooling scheme, but with the same design I doubt it can reach a real turbo anyway.

    Just don''t do this kind of thing on Mac Pro and I'm fine with Apple.
     
  22. kaintxu macrumors regular

    Joined:
    Jul 9, 2018
    #22
    Is that on the I9 with Vega 48?

    As I mentioned before, how does 4k look on the 5k monitor? my current iMac is a 2011, so no idea how 5K scales. All I know is that it is proportional to 1440p more than 4k, and heard is better to run the games like that?
     
  23. WrightBrain macrumors regular

    WrightBrain

    Joined:
    May 30, 2009
    #23
    Hey, I was concerned about heat and was considering using Turbo Boost Switcher as well. How much does It decrease performance? Is it noticeable?

    Do you turn off TB for games?
     
  24. BigBoy2018 macrumors 6502a

    BigBoy2018

    Joined:
    Oct 23, 2018
    #24
    Doesnt seem to decrease real world speed at all
     
  25. BigBoy2018 macrumors 6502a

    BigBoy2018

    Joined:
    Oct 23, 2018
    #25
    Yes, games like fallout which are demanding, I do turn it off.
    Also for long video remders. Witb a video remder i can turn it on and off and almost immediately when i turn it on the temps jump up and the fans go from 1200 or so rpm to 1800 or so rpm.
    It doesnt however have any impact of the ‘estimated time remaining’ of the render.
    Thats made me kind of conclude that turbo boost is a bs teick to make a processor look better in benchmarks, but is borderline useless in the real world. Thats why i now will always looks for the hiher clock speed of a certain generation of chip, and ignore tha geekbench scores for the most part.
     

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32 March 29, 2019