rMBP: Ridiculous core speed throttling when magsafe connector plugged in... HELP!

Discussion in 'MacBook Pro' started by Oxomoco, Jul 15, 2013.

  1. Oxomoco, Jul 15, 2013
    Last edited: Jul 15, 2013

    Oxomoco macrumors newbie

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    Jul 15, 2013
    #1
    Hi guys, sorry in advance for this mammoth post.

    Basically i've tried everything, but the only thing i've found that stops the throttling when playing games that require a fair bit of CPU, is playing on battery. So i've come to the conclusion that the problem must lie either with my charger, or the magsafe port and something to do with that. This is mainly while playing Steam games in bootcamp, i never really use OSX for high intensity CPU programs, so i'm not entirely sure if it throttles like this on the mac partition... But regardless, a powerful machine like this SHOULD be able to play these games for more than 10 minutes without throwing a total hissy-fit. This can't be normal.

    I've scoured the forums and i can't find anything that's worked. I've got good ventilation, and temperatures tend to hang in the mid 60s when gaming, which doesn't seem too hot to me, yet my 2.3Ghz is constantly being throttled down to around 1.1Ghz, which makes games stutter and totally unplayable. I'm not talking about Crysis or anything here either, i mainly play Chivalry, with the settings turned down so low it looks like it's from 1998... But it doesn't seem to matter what game, when the power cable is plugged in, the throttling is persistent as soon as it hits 67 degrees or so.

    I've tried PRAM and SMC resets, i have good ventilation, i have the fans maxed out and i've recently cleansed it of dust, i've tried programs like Throttlestop, forced Pstate 1 in Nvidia Inspector, reduced the max processor state to 95%... you name it, i've tried it. Everything short of reinstalling Windows partition, which would be a major pain in the arse. I can't say for sure whether it's the magsafe port, but all i know is that i can play perfectly stutter free until the battery runs out, and the very moment it's plugged, i start getting GPU throttling.

    Some other points worth noting are that i experienced this problem from the get go, but managed to fix it using fan control and Throttlestop, and now it's back with a vengeance, and nothing bar playing on battery seems to stop it.

    There is a heatwave at the moment, but if this were the problem then how on earth could people game in a climate even remotely hotter than grey Britain... In fact, i'm certain that with the fan control and better ventilation, my macbook is significantly cooler when gaming than when i got a good few months of stutter free gaming by using throttlestop... yet it's more aggressive than ever.

    FINALLY it's probably be worth noting that the wire sheathing on my magsafe plug has ripped near the base of the connector, exposing the wires, so i patched it up with electrical tape. I need a new connector, whether it's causing this problem or not, so i'm off to buy one tomorrow hopefully, but is it even possible that this is causing the throttling? Maybe it's just me but the magsafe plug does feel hotter than it used to, but i never really gave it any mind before... The only other possible thing i've done recently that may have caused it is recently reinstall Skyrim with a whole load of mods, which has only left me with about ~2.5gb free space on this partition. Needless to say Skyrim isn't even remotely playable.

    Anyway, any help, advice new perspectives or similar stories would be greatly appreciated because this is driving me potty. All my eggs are in the new power cable basket at the moment, i'll ask while i'm there but I have a feeling that bringing it up at the apple store won't help much. I've already had to have my original rMBP replaced within the past year...
     
  2. hobbbz macrumors 6502a

    hobbbz

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    Mar 8, 2005
    #2
    2 years ago or so with MBPs the power worked like this:

    If you played a game the CPU could ramp up its power and draw more Watts than the charger could provide, so while plugged in you could actually drain your battery.

    Regardless of convenience this really troubled a lot of customers "I'm plugged in why is it draining!" So Apple changed the power management so that when plugged in your CPU can only draw up to the Wattage provided.

    I reckon there is no such limitation on battery though because you know you're draining the battery if you're unplugged.
     
  3. Oxomoco thread starter macrumors newbie

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    Jul 15, 2013
    #3
    Ah interesting, that makes sense. But that still leaves me puzzled as to why it's suddenly, seemingly spontaneously returned, after i managed to solve this problem (although to a lesser degree) a few months ago. I was playing games fine while plugged in, without half of the new measures i've taken to boost performance and cooling. If a new power cable doesn't solve this then i'm positive there really is something wrong, as the majority of rMBP users aren't experiencing this...
     
  4. hobbbz macrumors 6502a

    hobbbz

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    #4
    Take it to the Apple store and play a game there on their cord. If it works fine buy a new one.
     
  5. Oxomoco thread starter macrumors newbie

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    Jul 15, 2013
    #5
    Sage advice. I've almost convinced myself now that the cord is the root of the problem, which probably wasn't all that wise. Time will tell...
     
  6. Astroboy907 macrumors 65816

    Astroboy907

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    #6
    Have you checked the energy saver settings for when it's plugged in? I'm not a retina expert but I think you can set which graphics card to use based on the method of power. Probably not the cause, or my memory of the settings might be flawed but it'd be worth a look...
    Edit: probably wouldn't cause your processor cores to throttle, more of a GPU thing...
    What wattage is your charger? Should say on the power brick somewhere...
     
  7. Oxomoco thread starter macrumors newbie

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    Jul 15, 2013
    #7
    Hey thanks for the reply. The power brick, which is extremely hot right now, says it's 85w. Even now, it's been idle for hours and the temps are pretty high. Here are a couple of screens i took in the last half an hour while just browsing the web. Obviously the core speed is stable as it should be, but it doesn't feel quite right... so i'm just going to leave this here in case anyone spots anything out of the ordinary...

    http://i.imgur.com/Fb1qHlO.png -- I had the fans set to max in the screen on the left and all the max temp values are from testing out the throttling a few hours ago.

    And yes, i have checked and tweaked the energy saver settings to the best of my knowledge, and i'm pretty certain i've got the graphics cards set up right, but i've been a Mac user all my life, so i'm not the most proficient at working in Bootcamp. If you were referring to the energy saver settings in OSX then i haven't touched them recently as i rarely do anything that CPU intensive on the Mac partition other than the odd Illustrator/Logic project, which on the whole work fine.
     
  8. nickandre21 macrumors 6502a

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    Jun 21, 2012
    #8
    Its normal for the brick to get hot. Mine gets equally hot that it gets uncomfortable to pick it up to wrap the cable.
     
  9. Oxomoco thread starter macrumors newbie

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    Jul 15, 2013
    #9
    Unfortunately swapping the cable didn't make a jot of difference. It's just as bad as before. It's very irrational, i just tried testing it again on a game that i used to play fine and now it seems that the fluctuations occur whether it's plugged in or not.

    Surely fluctuations like this aren't normal. http://imgur.com/ALIE40c

    This is after forcing the clock at 740Mhz, which seems to be pretty stable, but the core speed is all over the place...

    Guess a trip to the genius bar is in order although i don't have very high hopes...
     
  10. Doward macrumors 6502a

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  11. Oxomoco thread starter macrumors newbie

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    Jul 15, 2013
    #11
    ~65°C when gaming apparently, occassionally some of the cores will reach 70 odd.

    Interestingly enough, i've just tried playing Borderlands on the Mac partition for 10 minutes and despite the spinning beachball of death while it was loading up, the game seems to run stutter free. Whereas playing any remotely CPU intensive game on Bootcamp, and the throttling begins almost immediately...

    I'm not sure what's a good program to monitor core speed or temps in OS X but here's a screensnap just after quitting Borderlands. Much cooler, and the CPU in seems to have been under much less stress, but it doesn't exactly look like it runs at a stable level.

    http://i.imgur.com/cmHo8As.jpg
     
  12. Astroboy907 macrumors 65816

    Astroboy907

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    #12
    Looks to me as if it has everything to do with something in bootcamp..
     
  13. Oxomoco thread starter macrumors newbie

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    #13
    Sadly, that's what it's beginning to look like, or at least the way that bootcamp interacts with the OS is accentuating what may be an underlying problem. I experienced issues like this before on OS X, but it seems that SMC resets temporarily solve it, but no luck with that in Bootcamp.

    There have been quite a few reports of an EFI update causing throttling problems in certain MacBooks. Seems to me like i'm one of the unlucky ones as it's clear that the majority of rMBP users aren't experiencing this problem.

    http://appleinsider.com/articles/12...-complain-of-graphics-issues-after-efi-update
     
  14. EricT43 macrumors regular

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    Oct 5, 2011
    #14
    Have you tried downloading and installing the latest Bootcamp drivers?
     
  15. falcn macrumors member

    falcn

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    Aug 6, 2011
    #15
    Oxomoco, I had similar problem.

    It turned out that bootcamp had stuck in power saving mode somehow.
    You need to reset either PRAM or SMC, I didn't remember which of them, so reset both.
     
  16. Oxomoco thread starter macrumors newbie

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    Jul 15, 2013
    #16
    No actually i haven't. I feel like i'm up to date, but it's absolutely worth a double check.

    Hmm. Thanks, the the thing is though that i've already done countless resets of both to no avail. I guess once more can't hurt though...
     
  17. falcn, Jul 16, 2013
    Last edited: Jul 16, 2013

    falcn macrumors member

    falcn

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    Aug 6, 2011
    #17
    I have 15" rMBP.
    I use win7 x64 in bootcamp for games.

    Sometimes, Windows get stuck in what feels like some kind of power saving mode, for no obvious reason. I get 1/4 - 1/5 of my normal fps. Mac OS X gaming performance is not affected. When it happened to me first time, I spent two weeks trying to locate the problem and fix it. I replaced all drivers etc…spent hours looking at windows power management settings…
    Nothing helps except SMC/PRAM reset (can't remember which one of the two, I think SMC)

    It happened to me 3 times in a year.
     
  18. EricT43 macrumors regular

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    Oct 5, 2011
    #18
    Just reading through this post again, is it correct to say that the problem only occurs in BootCamp, when running a game, while the power cord is plugged in? And playing Borderlands 2 in OSX did not exhibit the same problem?

    If that's the case, then it seems that the power management in Windows is what is causing the problem. The fact that it only occurs when plugged in makes it seem like it's a power management issue. Hopefully installing the latest chipset drivers will solve that issue. If not, I would suggest that you reinstall Windows as a next step.
     
  19. Oxomoco thread starter macrumors newbie

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    Jul 15, 2013
    #19
    Hey man, thanks for your help. I've just got to finish some stuff on OSX first then i'll try some more SMC/PRAM resets, check the drivers and see what happens.

    You're partially correct, i think you both might be onto something with the power management issues, when i started the thread i thought that the aggressive throttling only happened when it was plugged in, however i tried to play Chivalry again a couple of hours ago and the throttling was immediate, with or without a power cord. But power management issues in bootcamp are looking likely as it seems that OSX can handle a CPU intensive game with little to no stuttering, although i've hardly tested this very thoroughly..
     

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