Heat issues - Bottomless + DIY Filter

Discussion in 'Mac mini' started by dasx, Nov 24, 2012.

  1. macrumors 65816

    dasx

    Joined:
    Jun 18, 2012
    Location:
    Barcelona
    #1
    Hey there.
    As a lot of you already know the i7 Mini is an oven. There are several threads in which it's been discussed its temps and how to deal with them under full load.

    philipma1957 and Snowcake are two who have been on the issue with special interest.

    In my case, a 2.6GHz i7, I was getting temps between 99-104ºC under full load.

    Here's a post in which, running Prime95 for 15 minutes I get CPU at 100ºC+ (although 98ºC are shown in the screenshot) and fans speeds of 5500 RPM in order to keep that temp. (Sooo noisy).

    [​IMG]

    It's not that that's unacceptable but thought I could do something about it.

    I mentioned in a couple of threads that I had bought a spare Mini Bottom cover off ebay and planed to mod it in order to achieve better temps and lower fan speeds.

    My intention was to remove this zone with a dremel and see a hell of an improvement.
    (Air is supposed to be swallowed in by the Mini through that red zone, in which the Antenna plate is)

    [​IMG]

    Did mod it but there was no improvement AT ALL. Still the same.

    So I decided to go another way and bought a fiber tiny net:

    [​IMG]

    Put two in a 45º 'polarization' which resulted in:

    [​IMG]

    I then took the bottom of the Mini off and put this custom air filter:

    [​IMG]

    For those wondering I attached it with a glue pistol so all the Air in has to go through the filter.

    [​IMG]

    This glue is extremely easy to remove and clean later on. This way I can remove this filer once every two months or so, clean it up and put it back with more glue.

    Raised the Mini 3cm with four rubber pads and this is what I get now:

    As you can see (after 30 minutes of Prime95), temps have dropped like 10ºC (they were between 87ºC and 95ºC all the time but mostly around 90s) and which is more amazing is that the fan just needed to spin at 3300rpm in order to keep those temps.

    Tried to manually put it at 5500rpm and temps went down to around 82-85ºC. Too much noise though. Not worth it.

    [​IMG]
     
  2. macrumors 603

    philipma1957

    Joined:
    Apr 13, 2010
    #2
    GOOD RESULT! I still go with the laptop cooler and remove the black plate. I may combine your idea with the cooler.
     
  3. thread starter macrumors 65816

    dasx

    Joined:
    Jun 18, 2012
    Location:
    Barcelona
    #3
    Yeah. I wanna try putting a quiet USB fan pointing at the bottom and see if that makes any difference.
     
  4. macrumors member

    Joined:
    Nov 18, 2012
    #4
    Is this heat and noise only a problem with the i7?

    Does the 2012 i5 have these problems too?

    With this and the hdmi issue Apple seem to have really messed up here.
     
  5. macrumors 603

    philipma1957

    Joined:
    Apr 13, 2010
    #5
    the i5 is fine.

    the i7 only has issues if cpu is pushed hard.

    ie handbrake is a commonly used program that will use all 8 threads.
     
  6. macrumors member

    Joined:
    Nov 18, 2012
  7. thread starter macrumors 65816

    dasx

    Joined:
    Jun 18, 2012
    Location:
    Barcelona
    #7
    It's not really an issue as the CPU manages to keep itself below 105ºC, but Mini gets as noisy as a jet taking off (5500 rpm) and temps go around 100-103ºC, which is A LOT.

    That's why I wanted to do something about it. A CPU working at 90ºC under full load will live longer than another one working at 100ºC. Also, fan staying in low 3000rpm is much more quieter! (Main reason tbh) :)

    Plus with this filter I got all air enters covered. With the default bottom cover dust gets inside the Mini pretty easily.
     
  8. propower, Nov 25, 2012
    Last edited: Nov 25, 2012

    macrumors 6502

    Joined:
    Jul 23, 2010
    #8
    First off - nice job on the filter! (though I fear there will be discoloration from the glue after a time)

    I too have taken the bottom off and blown fans in. Not as dramatic an improvement as I was hoping (love to get 60degC CPU at 50% load).
    FWIW I have found that the heatsink right near the back (you can just feel a little of it feel it with the cover off) is where the build up is. Blowing or ventilating in other areas has little effect.
    With the cover off the noise from the mini is much greater.
    What was most effective for my kinds of loads was taking the internal fan up to 2400rpm (or more - noise becomes noticeable at 2800rpm for me). The internal fan has the only real path to drive air over the cpu heat sink. If we wanted external fan, no back cover cooling it would actually be better to take the internal fan and cowling out!

    But keep up the good work!

    From a practical POV 90degC is less stress than 100degC. (85% of Tj,max vs 95%)

    In my application (pro audio) I am looking at doing a constant load (lets say 25%). The mini by design will spin fans to about 2000rpm (nice and quiet) and regulate the CPU temp at 90 to 94degC. If one ran a machine like this 4 hours a day for a couple of years, would there be any issues or is this just fine in todays CPU world? The hardest part of this is that all will agree it is not optimal but is there any real evidence as to how "bad" it is?
     
  9. thread starter macrumors 65816

    dasx

    Joined:
    Jun 18, 2012
    Location:
    Barcelona
    #9
    I'm pretty sure these CPUs could take 100ºC constantly for 3 years. Is it better to have it at 90ºC? Sure, and that's why I did all this plus letting the fan spin at half speed, which allows me to be around the Mini without having to cover my ears, lol

    Also, have you tried if a 25% of CPU use puts the CPU at 95ºC? I could try it now but I'll get a biased temp as I'm running with this mod...
     
  10. macrumors 6502

    Joined:
    Jul 23, 2010
    #10
    I have no proof but "engineers intuition" says - partly based on the 2011 mini and all the 2011 MBP's - that although this is a not so great thermal design it must have pretty good 1 to 3 year kind of life. If not there would be piles of internet evidence about mass death of these machines. I am starting to wonder if I looked at the mini as a keep under Applecare replace every couple of years machine it might be just fine. My only alternative is the MacPro (I have used towers for 12 years because I used to run pro audio PCI cards). Dollar wise I could repeat this buy sell buy cycle for a long time before I hit the price of another MacPro.

    Yep - 25% gets me low 90's with the cover on and fan at default. Even 15% gets me close - the fans don't start raising until 90degC is hit! Raising fans to 2400rpm at 25% load lowers that ~10degC. Cover off lowers a little further (might have been 10 more degrees -- need to document better :).
     
  11. macrumors 6502

    CHAOS STEP

    Joined:
    Nov 2, 2005
    Location:
    playing tiddlywinks with Kim Jong-un
    #11
    I've been wanting to get the new mini very badly, but I have (just) managed to restrain myself, while I look at the issues that people have raised.

    I'm not sure how long I can hold off for, I fancy the 2.6 but there are some good deals on the 2.3 that I can't ignore.

    As and when I do get mine, rather than fix a filter, can't I just raise the mini and inch (I'm thinking some Lego bricks used as risers or some other way to raise it but letting air circulate), and then just not having a cover on at all. Is dust a real issue the reason why you choose to have a filter?

    Thanks for all your input btw.
     
  12. thread starter macrumors 65816

    dasx

    Joined:
    Jun 18, 2012
    Location:
    Barcelona
    #12
    A filter is pretty mandatory imo. Otherwise dust will get in and obstruct the fan itself (not completely, but will eventually slow it down and/or make it work harder in order to keep speeds therefore a higher probability of failure) as well as blocking air circulation.

    You'll notice the Mini getting hotter and hotter with top temps hitting a new record every month. (Not 5ºC per month, but it'll definitely be noticeable over a 3 year time period).

    Check my OP. That custom made filter is damn simple. Just get a tiny net at your local hardware shop and stick it with tape if you don't wanna go the pistol glue road.

    I tried bottomless first and couldn't see even 1ºC difference in temps after installing the filter.


    (FYI, whole process took like 10 minutes)
     
  13. macrumors 6502

    Joined:
    Jul 23, 2010
    #13
    FWIW: I gave up! I hooked my 2009 MacPro back up and am returning the mini. I can't say whether it is a worthy design or not for my uses but after thinking way too much about it I have decided that it just isn't a good enough design for me to switch.

    Will be curious what comes next because if not the mini, and I don't like all in ones so no iMac, and I don't need a laptop so no retina and the 2013 MacPro will be WAY overkill and probably very expensive... hmm... I actually have no idea what will be next for me...

    Best to ALL... thanks for the discussions!
     
  14. thread starter macrumors 65816

    dasx

    Joined:
    Jun 18, 2012
    Location:
    Barcelona
    #14
    Sorry to hear. But if it didn't fit your needs then you did fine.
    Next? Well… Minis took more than a year to get an update and they got incredible specs, so I can see them staying like this for 15+ months…

    Does your 2009 Mac Pro stay behind? Does it really slow you down? Cause if not you can always wait another iteration of the Mini and see. You can save money in the meantime and if the next Mini doesn't fit you either you can always go for a new Mac Pro.
     
  15. macrumors member

    Joined:
    Oct 31, 2012
    #15
    Thinking of doing the same but just Dremel the entire bottom off the cover instead of the red bit you proposed....this way it should look a bit cleaner...

    Should yield similar results????
     
  16. macrumors 6502

    Joined:
    Jul 23, 2010
    #16
    The 2009 MP never slowed me down. The 2009MP and the mini are very close spec wise. The mini was hopefully a move to a smaller form factor. If needed in the future I can actually upgrade the MP to a six core Westmere and 48G ram.

    Best to all!
     
  17. thread starter macrumors 65816

    dasx

    Joined:
    Jun 18, 2012
    Location:
    Barcelona
    #17
    Definitely (You'll still have to raise it though). I was gonna try the same but got lazy and opted for this other option. I kept my modded bottom cover so might do it eventually just to test it out.

    The bottom part isn't visible at all in my case, (not even the top is too visible…), so I don't really care how the bottom looks. :)

    There you go then. ;)
     
  18. macrumors regular

    Joined:
    Nov 20, 2012
    #18
    Sometimes the most obvious solutions are the hardest to see. Heat rises. The heat sink in the mini is fairly massive so most likely you would only need to find a better way for it to escape easier. Has anyone tried to place their mini vertically, so the bottom can dissipate heat better :confused:
     
  19. macrumors 603

    philipma1957

    Joined:
    Apr 13, 2010
    #19
    yes and vertical mounting with the black plate off and a fan drops it 15 to 18 f. these 2 come to mind


    http://eshop.macsales.com/item/NewerTech/NUSTALYMINI/


    http://www.amazon.com/Thermaltake-M...166&sr=8-1-fkmr0&keywords=thermaltech+usb+fan



    http://www.amazon.com/Thermaltake-M...353954199&sr=1-2&keywords=thermaltake+usb+fan
     
  20. thread starter macrumors 65816

    dasx

    Joined:
    Jun 18, 2012
    Location:
    Barcelona
    #20
    I don't think a vertical Mini will get better temps than an horizontal one. Not with the bottom on in both cases. Maybe 1ºC drop? I don't think that would even happen.

    It'd be nice to find out though. :)
     
  21. macrumors newbie

    Joined:
    Oct 18, 2012
    #21
    Has anyone given any thought to attaching a heat sink to the top of the mini with a fan blowing across it. Probably not the prettiest solution but might be quite functional.
     
  22. macrumors 68030

    MrXiro

    Joined:
    Nov 2, 2007
    Location:
    Los Angeles
    #22
    That's the ugliest damn bong I've ever seen... :p
     
  23. macrumors regular

    Joined:
    Nov 20, 2012
    #23
    A fan would introduce more noise, which I think is why they want to cool down their minis (because the fans are running constantly). What would probably work, although I don't know the technical name for them, are those inserts that you see in hot/cold coolers that either keep picnic food hot or cold. Placing one of those on the mini should absorb the heat like a sponge, especially if you cooled it ahead of time. That would be noiseless and functional.
     
  24. thread starter macrumors 65816

    dasx

    Joined:
    Jun 18, 2012
    Location:
    Barcelona
    #24
    You don't see it unless you put the Mini upside down so it's fine with me as I don't intend to.

    ----------

    I can recall Snowcake doing something like that. (Or wasn't Snowcake).

    Well, apparently it didn't make such an impact on the temps.
     
  25. macrumors 68030

    MrXiro

    Joined:
    Nov 2, 2007
    Location:
    Los Angeles
    #25


    I was kidding... it's a line from a TV show.

    I was thinking about doing something similar... but I'm not sure if I'm having heat issues to be honest. I have the i7 2.3 and I never hear the fans unless I am using Handbrake and I figure that's a non-issue.
     

Share This Page