Feelin HOT HOT HOT

Discussion in 'Mac mini' started by campuscop2003, Apr 21, 2012.

  1. campuscop2003 macrumors newbie

    Joined:
    Apr 11, 2012
    #1
    :eek:

    So was working in lightroom and a few other programs and notice my CPU Temp got to 205F. Im guessing this in normal?? Scared the hell out of me so I installed the SMC Fan Control Program and set the fan to 4000RPM until the temp got down to 120F then set the minimum to 2100RPM. Anyone else using this program? What do you have your minimum set to. Dont want to wear my fan out or anything. Thanks!
     
  2. chrono1081 macrumors 604

    chrono1081

    Joined:
    Jan 26, 2008
    Location:
    Isla Nublar
    #2
    Processors have an auto shut off feature, if they get too hot they'll shut themselves down, but you'll notice stuttering and lag before this happens.

    No need to worry unless you get stuttering and lag.
     
  3. GGJstudios macrumors Westmere

    GGJstudios

    Joined:
    May 16, 2008
    #3
    Your Mac is not overheating. The Intel processors used in Macs are designed to automatically shut down to prevent damage if they truly overheat. CPU Tjmax = 105C, GPU Tjmax = 100C on i3, i5, i7 processors. (Source: Intel) If you're not already using it, iStat Pro will give you accurate readings of your temps and fan speeds, among other things.

    Unless there is a rare defect in a Mac, most temps are well within the normal operating range, considering the workload being put on it. Websites with Flash content, games and other multimedia apps will put higher demand on the CPU/GPU, generating more heat. This is normal. If you're constantly putting high demands on your system, such as gaming or other multimedia tasks, expect temps to rise and fans to spin up accordingly. It's just your Mac doing its job to maintain temps within the normal range.

    It is also quite normal for your Mac to become extremely hot to the touch during intensive operations. The aluminum body transfers heat more effectively than other materials used in computer casings, so you will feel the heat more. This doesn't indicate that it's overheating and will not harm the computer to be hot to the touch.

    Your fans are always on when your Mac is on, spinning at a minimum of 2000 rpm (for MBPs) or 1800 rpm (for MBAs, MBs and minis). iMacs have 3 fans with minimum speeds in the 800-1200 range. They will spin faster as needed to keep temps at a safe level. If they're spinning up without increased heat, try resetting the SMC. (PRAM/NVRAM has nothing to do with these issues, so resetting it will not help.)

    The intake and exhaust vents are in the back of the computer near the hinge on all Mac notebooks. The iMac vent is a slot on the back near the top of the computer. Make sure the vents remain unblocked to allow your computer to perform at its best.

    Learn about the fans in your Mac
    Apple Portables: Operating temperature

    For Flash-related issues:
     
  4. Ruahrc macrumors 65816

    Joined:
    Jun 9, 2009
    #4
    What you say is correct, but a CPU run at its thermal design limit often is going to shorten its lifespan. IMHO the default SMC settings in the mini are too slow to compensate for heat load and ramp up the fan, which cause unnecessary jump.

    With modern CPUs like the sandy bridge, with advanced power management features, the thermal load of the CPU can change drastically from one instant to the next. For example, you are browsing the web and the CPU has shut down half or more of its cores, and lowered the voltage to an economical setting. Then you start up handbrake to encode videos and BAM- the CPU engages all cores, and jumps the voltage to the normal operating level.

    In cases like these, the CPU can increase in temp by 30-40C in a matter of seconds (you can watch it happen with iStat nano/pro), particularly when they are coupled to low-mass coolers like are seen in compact systems like the mac mini.

    I have run tests where starting a 1080p video playback or starting encoding causes the CPU temp to quickly jump from normal temps of 45-50C up to 95C in just a few seconds and the fan will take 10-15 seconds to fully ramp up to the maximum of 5500rpm. There it cools the CPU down to about 70C and the fan lowers way down (say 3000rpm), but the continuous load on the CPU means the temp is soon back up to 95C and again the fan is too slow to respond, so it overdrives to 5500rpm and cools it down, and the cycle repeats.

    Whereas if you preset the fan to a higher level like 4000rpm, the CPU only jumps to about 80C and the swings in temperature are not as extreme, because it's not constantly "chasing its tail" so to speak. If the feedback loop was more aggressive in detecting rising temps, it would not swing around nearly as much.

    Because of the very fast temperature swings of the CPU, the automatic fan control also seems to operate almost in a bi-modal state. Either it is "cool" and at or near the default speed of 2000rpm, or the CPU has jumped to 95C and the fan ramps to 5500rpm to cool. There is not much time spent in between.

    I don't do anything special for my usage since most of the time my mini is in a near-idle state, but I do wish the thermal feedback loop that controls the CPU fan was a bit more aggressive with increasing heat load. If you do plan on starting a high-load job, maybe run SMCFanControl and set a higher default fan speed. You would experience fewer wild swings in fan speed (and resulting noise) and the CPU temps on the mini will be more stable over time.
     
  5. GGJstudios macrumors Westmere

    GGJstudios

    Joined:
    May 16, 2008
    #5
    It depends on how often. Most Mac users are not going to run at the limit for even 10% of the time they use their Macs. Any shortening of lifespan would be so minimal that it's quite likely that an average user would have sold the Mac years before they'd see the end of its useful life. Also, spikes in temps many times will not cause fans to ramp up. Usually, temps must be sustained at a higher level before fans will spin faster. While nothing is impossible, I've never heard of any Mac dying because of heat issues, unless there was a manufacturing defect involved. And that's with no 3rd party apps interfering with the default temperature and fan management that comes built-in.
     
  6. campuscop2003 thread starter macrumors newbie

    Joined:
    Apr 11, 2012
    #6
    I changed the minimum fan speed to 2500rpm. Coming from a desktop that I built with 8 fans that's sounded like a vacuum cleaner, my mini running at a higher fan rpm isn't going to bother me in the least. This my first Mac and all so I know they do things a little different, however I would rather it be cool rather than quiet, and the jump to 205f was more than I am comfortable with, limit or not.
     
  7. lilsoccakid74 macrumors 6502

    Joined:
    Apr 13, 2010
    #7
    Since 1800rpm is default on the 2011 models (maybe slightly higher on the server), I made light(2000), mid(3000) and heavy(4000) settings.

    I run mine with the bottom removed and a laptop fan to blow air up through the bottom, keeps it about 60*C while gaming, when usually 95*+ :) This is obviously not necessary, but without it the stock fan gets way too loud for me to hear anything.
     
  8. frank4, Apr 22, 2012
    Last edited: Apr 22, 2012

    frank4 macrumors regular

    frank4

    Joined:
    Oct 17, 2011
    #8
    I'm running a different utility, "Fan Control" by Lobotomo (free, open source). It automatically and gradually raises fan speed as the temperature rises, according to user preferences. I've set mine to start raising the fan speed from base 1800rpm at 50C to 6000rpm at 80C. The Mini fan will not actually be able to spin that fast but will get up to about 5000rpm as I recall from testing a few months ago. Unlike the standard Mini cooling which seems to be slow in responding to heat, Fan Control can often be heard raising the fan speed slightly when the CPU temperature rises.

    The nice thing about Fan Control is it is automatic and increases fan speed only when necessary, so usually the speed just sits at base 1800 to 1900. I don't want to continually worry about making manual adjustments to the fan speed depending on the CPU workload. I think smcFanControl always runs the fan at the same speed regardless of load.

    http://www.lobotomo.com/products/FanControl/

    I don't like the idea of computers running hot. The CPU and other chips may be able to take the heat, but what about the circuit board? They use tiny solder joints and copper circuit lines that can become defective because of thermal warping. That's exactly what happened to my friend's MacBook - it died after 1 year due to a bad connection to the CPU or graphics chip caused by high temperature. No help from Apple on this one, he had to buy a new machine.
     
  9. MJL macrumors 6502a

    Joined:
    Jun 25, 2011
    #9
    I have personally owned15+ laptops (Thinkpads, Tecra's), had 400 staff and was responsible for 1000+ desktop/laptop purchases in a year. Prior to that I also have an electronics manufacturing (QA) background.

    I have NEVER heard so many stories about motherboard failures as with Apple.

    If a motherboard would fail and Apple would refuse to replace (even out of warranty) I would take them to the small claims court. Asking premium prices yet deliver crappy (although nice looking) gear is not acceptable in my book.

    There have been courtcases in our country where the vendor had to replace a motherboard out of warranty after 3 years. Similarly there was recently a courtcase where someone got his MacBook replaced that had the faulty NVIDEA GPU in it and he wanted either his money back or another motherbaord that did not have the faulty chip in it.

    Heat does destroy hardware - check out what is written about reliability of CPU's by Intel with the ever decreasing size of components (with Ivy bridge now going to 22nM where the theoretical limit is 14nM) and the effects on the dielectric between the components.

    But there will always those that are not willing to accept the truth about the effects of thermal cycling.

    To the OP: Try to keep the temperature below 75C by using a third party fan controller. The server is running at 2300 rpm and is staying pretty cool. Do not have permanently other gear attached that sip power, the power supply is moderately efficient and generates extra heat (e.g. Firewire HDD, USB HDD) and if possible do not use wireless or bluetooth. Elevate the mini a bit above your desk and ensure that the fan is not clogging up.
     
  10. philipma1957 macrumors 603

    philipma1957

    Joined:
    Apr 13, 2010
    Location:
    Howell, New Jersey
    #10
    I gave you a plus. You are correct too much heat is bad. People may say that mac minis can run at 95c safely yeah they can in the short run.

    Buy the mac mini server run handbrake endlessly 24/7/365 let me see proof that you did. That server will not last 3 three years. Failure rate will be more then 40 %.

    I guess that number and have 0 proof. I am not buying 5 servers and testing them with handbrake till they drop. If some one wants to drop 5 k on the servers and 1 or 2 k in power to proof me wrong cool.

    Since most users don't run endless handbrake pushing the cpu at 95-100% for 24/7/365 these failures don't show up. Apple does not have to worry about high failure rates except for under 1 year.

    Now the stats I can give for 2011 mac minis that I have sold/own are 0 failures in about 100 machines. I keep stats and I have been upgrading minis since 2006 the first intels. The 2011 mini has had the best return rate of every mini I have sold. 1 return due to my install of a ssd (the sata cable came loose) I re did the work and that machine is working to this day. The other problem on 2011 minis has been some loose fan cables. 2 came like that and the third one may have been my fault. I now boot the first time with the mini upside down and black plate removed. Since I add ram this is a 1 minute pre-test. Lets me know the machine came working from apple.

    NO PC MAC OR WHATEVER HAS HAD THIS GOOD OF A RETURN RATE FOR ME

    I only track for a year. Since I sell the minis with a year of warranty on them. Minus a week for mods and turn around time.
     
  11. urkel macrumors 68030

    Joined:
    Nov 3, 2008
    #11
    Does putting it vertical or anything help with lowering heat? I love the mini but many design decisions feel more aesthetic than practical so I just want to figure out what I can do as an end user to cool it down.
     
  12. Fishrrman macrumors G5

    Fishrrman

    Joined:
    Feb 20, 2009
    #12
    "I have NEVER heard so many stories about motherboard failures as with Apple.
    If a motherboard would fail and Apple would refuse to replace (even out of warranty) I would take them to the small claims court. Asking premium prices yet deliver crappy (although nice looking) gear is not acceptable in my book."

    I'm wondering if the various complaints regarding "too much heat" on the Mini models are due to design "failures" that are similar to that of Apple's Time Capsules -- that is to say, they have cases that are designed for "style", rather than to provide the best cooling.

    The Mini has the removable plastic plate on the bottom to access the memory and presumably for air intake for the cooling fan, as well. But where does the incoming air EXHAUST from?

    I don't own a Mini yet, but will be buying when the Ivy Bridge models are released (to replace an OLD and VERY noisy PowerMac g4 tower). But just looking at the design, it seems to me that when used in it's "normal orientation" -- sitting on a desktop -- there isn't much space for air intake, and there seems to be very little at all (if any) for air exhaust.

    I'll be looking for some "alternative" method of placing it on the desk. Either by using some kind of "stand" that puts it on its side, or perhaps by "elevating" it horizontally for more airflow underneath. I've been thinking of putting together some kind of "cooling stand" which would incorporate a fan underneath (perhaps a quiet 120mm internal cooling fan for a desktop?) that would provide more airflow without much noise. I can see a market for a commercial product along that line....
     
  13. tshrimp macrumors 6502

    tshrimp

    Joined:
    Mar 30, 2012
    #13
    I am starting to get a little worried, but not too much so. I am a new Mac Mini owner, and have had no issues other than it is a little slow. But as you have stated there are a lot of heat issue posts (and my temps do get rather high), and I have never had any heat issue on the PC side. But I have usually built my own making sure there is plenty of air flow.

    I would assume some of the heat issue have to do with putting so much in a small package. This can't be good for airflow, but again I would think it would be in the safe area.

    Also after doing some research some have posted that the Mac Mini has a Foxconn motherboard. Is this true? On the PC side they are known as the "Junk" motherboards, so this also worried me a little. However the temps that most people are posting are usually withing the safe area for the CPU and I can't recall any time that my CPU was the issue for my failures. MB, RAM, HD, Power supply yes, but not the CPU (now that I have posted this I am sure it will be what goes on my next system. :)
     
  14. SR45 macrumors 65832

    SR45

    Joined:
    Aug 17, 2011
    Location:
    Florida
    #14
    Upped the fan speed to 2229 rpm only, room ambient temp around 77 degrees and my temps are...







    What are is your room ambient temps ? Higher they are, the higher the computer temps.
     

    Attached Files:

  15. tshrimp macrumors 6502

    tshrimp

    Joined:
    Mar 30, 2012
    #15
    I am about 51c(124F) on the CPU at 1800 rpm with amb temp of 80F. This is about as low as I ever see it. Gets in about 85C under some load. Watching Netflix. Do not remember fan speed, but you can easily hear it.
     
  16. campuscop2003 thread starter macrumors newbie

    Joined:
    Apr 11, 2012
    #16
    The ambient room temp at the time my average processor temp got to 205F was about 65F. I currently have the fan set at a min. of 2500rpm and have not seen temps go above 160F since. While surfing the net and doing minor things its around 113F. However once I see its at 160F I kick it up to 3500rpm and cool her down, so dont really know if it would have gone higher or not. I am really liking the SMCFanControl software.
     

Share This Page