MacBook Pro Clock Speeds

Discussion in 'MacBook Pro' started by tylamb19, Dec 6, 2015.

  1. tylamb19 macrumors member

    Joined:
    Dec 27, 2014
    #1
    Hi all,

    My faithful 2012 15" MacBook Pro is acting a little bit strange. I first noticed it really being sluggish in Final Cut Pro X a little while back, but since my project was really large, I thought that was the cause of the sluggishness, but it is not as I recently found out.

    My laptop seems to actually be clocking itself to exactly half of the CPU's advertised clock speed. The CPU is a 2.6 GHz i7-3720QM, but it actually is clocking itself at 1.3-1.4 GHz while in OS X. I thought this was really strange. I used the Intel Power Gadget to measure the CPU clock in OS X and used the Intel Processor Diagnostic live USB to measure it in Fedora while booted off of a USB drive.

    In OS X, the clock speed is stuck at that 1.3-1.4 GHz point (screenshots attached) but in Fedora, the clock speed is 2.63229 GHz, normal for the CPU. The first thing that I did after checking the clock speeds was to check CPU temps, but the Intel Power Gadget and diagnostic test reports 45-50ºC, again normal for the CPU. Next I checked the battery, which reports a normal condition. It is well known that a bad battery can cause halving of the clock speed, but that appears not to be the culprit here. After checking the battery, I reinstalled OS X on a separate drive to rule out a software issue. No dice. Clock speed is still 1.3-1.4 GHz. I work in IT for a school district that is an Apple SSA, so I ran ASD next. Completely passed both the EFI and OS diagnostics with flying colors. What???

    I think I'm going to drive myself crazy trying to fix this, as I am a video editor/programmer and a little bit higher clocked CPU can really boost performance in those areas, so doubling the CPU clock could do me wonders. Does anyone know what is going on here?

    Thank you for any help you can give!
     

    Attached Files:

  2. T5BRICK macrumors 604

    T5BRICK

    Joined:
    Aug 3, 2006
    Location:
    Oregon
    #2
    Modern CPUs only run at full speed when needed. When browsing the internet and performing basic tasks, my 13" 2015 rMBP bounces between 1.3-1.6GHz according to Intel Power Gadget. As soon as I fired up prime95 to stress the CPU, it shot up to 3.4GHz.

    *EDIT*

    In case you want to read up on it, Intel calls this function "Speedstep."

    https://en.wikipedia.org/wiki/SpeedStep
     
  3. treekram macrumors 6502a

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    Nov 9, 2015
    Location:
    Honolulu HI
    #3
    Concur with T5BRICK. If you have Handbrake, you can try running it and then see what the CPU speed is. (A Handbrake transcode will pretty much max out all your CPU cores.) Otherwise you can try a CPU-intensive multi-core benchmark that have comparative benchmarks published and see how your computer compares.
     
  4. tylamb19 thread starter macrumors member

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    Dec 27, 2014
    #4
    I know that CPUs only run at their advertised clocks when under load, I just forgot to mention that in OP. That said, I don't have handbrake, but I can use "yes" in terminal to max out my CPU cores. When doing this my CPU hits 1.40GHz and stays exactly there. Any more ideas?
     

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  5. tylamb19 thread starter macrumors member

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    Dec 27, 2014
    #5
  6. TheIguana macrumors 6502a

    TheIguana

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    Sep 26, 2004
    Location:
    Canada
    #6
    Two thoughts:

    1) Is your battery still functional? If your battery reads as dead or below 5% charge the computer automatically throttles heavily to the levels you are reporting. MacBook Pros do not function at full performance without a functional battery. Frustrating but it is just how they are engineered.

    2) Could be a hardware failure on your Logic Board. Mac's will often throttle down if something has failed on there. In this case you can try running Apple's Hardware Test to see if it detects anything. https://support.apple.com/en-us/HT201257
     
  7. DeltaMac macrumors 604

    DeltaMac

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    Jul 30, 2003
    Location:
    Delaware
    #7
    Not likely that the Apple Hardware Test will help the OP, who says he has run Apple's Service Diagnostics, (that's the ASD mentioned in the OP) which ran clean. That is a more in-depth diagnostics than the hardware test can ever be.

    @tylamb19 - Is there any possibility that you have had this problem since new, and only recently checked out the processor speed? Maybe you have had that issue since new?
    Does your battery show in your System Information/Power tab without noticeable issues - good charge cycle numbers, good charge available, etc?
    As memory can have some strange issues - do you have other known-good RAM that you can swap in, just for a test?
     
  8. Gav2k macrumors G3

    Gav2k

    Joined:
    Jul 24, 2009
    #8
    Op run the hardware test. This will let you knew if the issue is hardware related ie fan failing

    Given the age of your system when was the last time you opened her up and cleaned the dust out?

    To me it looks like heavy throttling which is usually fan or battery related
     
  9. treekram macrumors 6502a

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    Nov 9, 2015
    Location:
    Honolulu HI
    #9
    The OP says he ran Fedora (Linux) on the MBP and it runs up to speed. So if it's a hardware issue, it has to be a hardware issue that only would affect OSX and not Fedora. The OP also tried a clean OSX install (I assume a standard OSX and not one from the school district). Try PRAM/NVRAM and SMC reset?
     
  10. tylamb19 thread starter macrumors member

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    Dec 27, 2014
    #10
    1: Yes, I can unplug the computer and use it perfectly fine. 88% health remaining, 6106mAh/6900mAh. 223 cycles. Charged to 100% with charger plugged in, same issue.
    2: I have already run Apple Service Diagnostics, which is an extremely comprehensive hardware test. It can pick up more than the normal HW test AFAIK.

    It easily could have been since new. I haven't checked the CPU clock in the past, I only checked it after stuff felt really slow to me (editing a long project in FCPX). I just put 16GB of brand new RAM in a week ago. I can try the old RAM and see. For the battery info, see above.

    1: About the hardware test, see the second response to the first quote of this post.
    2: I have diligently cleaned out the machine, probably more than most people. Last time I cleaned it out was about a month ago. For the battery info, see above (first quote, first response)

    I have done a real, clean OS X install. I have done an SMC and NVRAM reset, nothing different clock speed wise.
     
  11. tylamb19 thread starter macrumors member

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    Dec 27, 2014
    #11
    Time to make this already strange thread even stranger... Installed a fresh copy of Windows 10 Pro in BootCamp. Installed CPU-Z and AIDA64 to see what we could get. The CPU is at 1197.14 MHz according to CPU-Z and the Intel Power Gadget while running an AIDA64 stress test. The clock won't go any higher than that exact number. Temperature was constant at 92ºC, so nowhere near the throttle point of 105º (I still did a test with the fans cranked to the max using Macs Fan Control, but it didn't change anything). Interesting... let's run the Intel CPU diagnostic. The CPU diagnostic reports a clock speed of 2.60818 GHz, so a pass for the clock speed test. Meanwhile, I still have CPU-Z and the Intel Power Gadget open. Both are reporting 1.20 GHz. What?!?!?!? Conflicting results aside, I might have to throw away the Intel CPU Diagnostic results as they seem to not be accurate.

    Also, I had a look at AIDA64's voltages tab and my CPU is running at 0.811V, so that is on the really low side of normal. Looking at the 12V rail on the power supply reveals 16.31V. This is a possible issue, but it might just be a monitoring error. Any advice or ideas?
     

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  12. treekram macrumors 6502a

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    Honolulu HI
    #12
    Did you notice the slowdown before or after you put in the new memory? I'd definitely try putting back the old memory back in - especially if you had 8GB (or less) before. Some people who used good-quality memory have reported problems with 16GB in their 2012 MBP.
     
  13. tylamb19 thread starter macrumors member

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    Dec 27, 2014
    #13
    Now that I think about it, I noticed the slowdown about two days after I installed the 16GB of RAM. The old RAM was 8GB. I will re-install it this afternoon and see what I can get.
     
  14. Gav2k macrumors G3

    Gav2k

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    Jul 24, 2009
    #14
    Did you by the correct voltage ram?
     
  15. tylamb19 thread starter macrumors member

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    Dec 27, 2014
    #15
    I replaced the memory again with the 8GB of factory-installed memory. No change in clock speed behavior. While I had the machine open, I unhooked the battery and checked the clock speed. I noticed that the speed was constant at 1.20 GHz with the battery unplugged, even while running yes in terminal 8 times at once to max out all of the CPU threads, but since the battery is unplugged, this is normal.

    I attached a picture of the new vs. old RAM as well, but AFAIK they are completely equivalent spec-wise (I could be wrong though).

    EDIT: I wonder if the constant 1.20 GHz frequency that I was seeing in Windows has some sort of relationship to the constant 1.20 GHz frequency that I was seeing when I had the battery unplugged...
     

    Attached Files:

  16. ayeying macrumors 601

    ayeying

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    Dec 5, 2007
    Location:
    Yay Area, CA
    #16
    You should try a Dell performance laptop. If your power supply is not the same as it came with the system, it'll throttle down to the lowest point and will not go back up even on battery mode entirely.

    OP have you tried a SMC reset?
     
  17. tylamb19 thread starter macrumors member

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    Dec 27, 2014
    #17
    First, I don't want to change my laptop. My MacBook Pro works great (even with the slow CPU clock) and looks great. This suggestion isn't really relevant to this thread either.

    Second, I am using the original 85W MagSafe 1 power adapter. This is the factory power adapter for the computer, and it will charge and operate my computer fine. I have done both an SMC and NVRAM (PRAM) reset, it didn't do anything.
     
  18. Kissmyne macrumors 6502

    Kissmyne

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    Apr 21, 2015
    #18
  19. tylamb19 thread starter macrumors member

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    Dec 27, 2014
    #19
    Already done. No change. I even manually reflashed both the SMC and EFI. Nothing different. Also, Apple Service Diagnostics usually pick up a corrupted EFI/SMC. A few MacBook Airs in the school district have had corrupted EFIs/SMCs, but that was the result of an unfortunate power surge while installing updates...

    Also, just for due diligence, I will test with a brand-new, known-good battery from a different (same year & specs) machine. I can get the testing done at some point in next few days or so.
     
  20. treekram macrumors 6502a

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    #20
  21. tylamb19 thread starter macrumors member

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    Dec 27, 2014
    #21
    I took a look at the thread, but my kernel_task CPU usage isn't incorrect... I did do an SMC & NVRAM reset after installing the original memory. The only thing connected when I did my tests is the charger.
     
  22. tylamb19 thread starter macrumors member

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    Dec 27, 2014
    #22
    YEAHHHH!

    The battery was the ticket!

    New battery = full on turbo boost for extended periods of time (see attached screenshot)!

    This really has been an experience. Not sure why or in what way the old battery was malfunctioning, or why ASD didn't pick up the issue.

    Either way, my MBP is ready to be a great computer again for years to come. Thank you all so much for your help and words of encouragement.

    EDIT: Attached the screenshot twice, whoops. Also, I have my 16GB of RAM in there too!
     

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