Aluminium iMacs overheating?

Discussion in 'Mac mini' started by Cloudane, Jan 18, 2008.

  1. Cloudane macrumors 65816

    Cloudane

    Joined:
    Aug 6, 2007
    Location:
    Sweet Apple Acres
    #1
    Just been into Second Life, which is a *very* graphics-intensive world. For a little while it was ok, but after a bit I started getting flashing/flickering textures everywhere.

    All research on texture flicker problems seems to point to overheating, which makes sense considering it didn't happen straight away and I've seen similar from failed GPU fans on PC's.

    Installed smcFanControl and set it to max on everything (jet engine time!! I had no idea iMacs could be that loud!) and went back in, and sure enough it was stable. Curiously, it's the first time I've actually felt any air coming out of the slot on the back of the unit, making me wonder if the temperature based fan control is even working at all.

    Another user on the SecondLife forum managed to fry his graphics chip just by playing it, which is not good. He now gets flickers and artifacts everywhere, even the desktop. It seems to me Apple have been a bit too conservative with the fan speeds to make the iMacs seem quiet, at the risk of frying people's GPUs if they play a graphically intensive game. This is probably also why thousands of people have been returning them with graphical glitches. Bad, bad Apple, but I digress.

    Can anyone recommend a safe level to set the fans at to keep the machine relative quiet but also prevent it from overheating / doing damage? Also, on full the fans go ridiculously loud/fast. Would this be causing excessive wear and tear on the fans? They're not exactly easy to change :eek:

    Secondly, what do I do under Windows, is there an alternative to smcFanControl that works for Macs under Bootcamp?

    Cheers
     
  2. vtprinz macrumors 6502

    Joined:
    Nov 30, 2004
    #2
    The vast majority of iMac users are never going to push the graphics chip that hard, and the heat conductive abilities of the aluminum enclosure allow the machine to run (under normal circumstances) with minimal fan speeds.

    I doubt it's a fault of apple in keeping the fans down, but rather more that you're just not the target audience, and the machine isn't specced for your demands. I know several gamers on the PC side that had to buy higher rated fans to put into their towers for this same problem. The only difference here is that you can't upgrade the iMacs fan, which is a shame, but being "all-in-one" is kind of the point of an iMac in the first place.
     
  3. PMR macrumors 6502

    PMR

    Joined:
    Sep 29, 2007
    Location:
    Portugal (Google it)
    #3
    Just set two profiles. One profile that puts hdd and cpu/gpu fans at 1800 or 2000rpm and another at around 2600rpm for games/video encoding.

    If you want to use these speeds in bootcamp, just set the profile you want in osx, RESTART (don't shut down) and hold alt, the fan speeds will continue in windoze
     
  4. RevToTheRedline macrumors 6502a

    RevToTheRedline

    Joined:
    Sep 27, 2007
    #4
    Wow.... Of all the posts I've read on the subject of iMac heat issues this has to be the most inaccurate post I've ever seen on the subject, now I'm going to be called an a**, but that was a ridiculous assumption.

    Cloudane, do what PMR said and there will never be an issue, I have 3 profiles set for depending on what I do, 1500/2500/2000rpm for default all around usage and I never run any lower than that. 2100/3500/2300rpm for video encoding and gaming, and a profile with maximum fan speeds in case I wanna do a fast cool down.

    The heat issues with the iMac have absolutely NOTHING to do with having incapable fans, or needing to "upgrade them" and it's not a design flaw either, it's just a simple fact that Apple choose to have a near zero noise computer out of the box rather than properly cooling it when doing intensive tasks. Nothing that can't be fixed with smcFanControl.

    So tell me, what is the target market of this machine?
     
  5. Washac macrumors 68020

    Washac

    Joined:
    Jul 2, 2006
    #5
    Hi Ya

    I play WOW for quite a few hours somedays and I run my fans all the time at the speeds below using smcFanControl.

    ODD 1500
    HDD 2500
    CPU 2000
     
  6. Cloudane thread starter macrumors 65816

    Cloudane

    Joined:
    Aug 6, 2007
    Location:
    Sweet Apple Acres
    #6
    I just knew some stupid fanboy would steam in telling me it's my fault for trying to actually run something on the thing (naughty me), and Apple would never put a foot wrong yada yada. Silly me, the "target audience" must only use iLife or just leave it turned off and admire its pretty curves! Software should not break hardware no matter what you throw at it, if it does then the hardware setup is incorrect. Tell me, what happens if a badly written app uses 100% of your graphics card then? Oh of course, Macs never have any badly written apps... god if there's one thing I HATE about Macs it's the fanboys... /rant

    Thank you for the constructive replies from everyone else :) I'm not massively impressed that it's set up to overheat if you run anything graphical (btw I wouldn't really call SL a game, more of an online world. It's sort of artistic... see, art! I am in their target audience!) - but at least with this thing running it's not going to be an issue anyway. Cheers.
     
  7. Queso macrumors G4

    Joined:
    Mar 4, 2006
    #7
    Ummmm, surely all Alu iMacs are still under warranty. Why not just get the logic board replaced?

    Is it a design fault? Maybe, but I would have thought all those people playing other graphics intensive games such as CoD4 would be having this issue if it were. More likely that a few iMacs are just more sensitive than they should be. Replace the board and the problem will likely go away.
     
  8. durija macrumors 6502

    Joined:
    Jan 16, 2008
    Location:
    Seattle
    #8
    Now I am worried

    After reading this post, I am starting to worry about my Aluminum iMac. Less than a month old. It always feels hot to me when I put my hand on the back. So I went to check out this smcfancontrol being discussed and came across this post:
    http://www.macupdate.com/reviews.php?id=23049
    Mixed reviews to say the least. I would like to be able to control and monitor my iMac's temp. Is this app really safe to use? Are there any other options?
     
  9. PMR macrumors 6502

    PMR

    Joined:
    Sep 29, 2007
    Location:
    Portugal (Google it)
    #9
    the last version of smcfancontrol works flawlessly in the new imacs if you don't have any software/hardware corruption.

    you should care about high temperatures as they limit lifespan at the long term, but i never saw any computer dying for being hot all the time. I have seen some suthdowns (induced by the computer as safety measure) and and video artifacting, but no deaths. My brother's old imacs g3 and g4 were hot as hell and they all keep running.

    Just install smcfancontrol and raise rpms a bit, but don't worry too much about it.
     
  10. durija macrumors 6502

    Joined:
    Jan 16, 2008
    Location:
    Seattle
    #10
    Installed Temperature Monitor, ran an intense graphics app and saw the temps fly up like rockets. I think I will give smcFanControl a try. Version 2.1.2 appears to be the latest. Thanks for the nudge. Plunging now...
     
  11. nickf macrumors member

    Joined:
    Oct 2, 2007
    #11
    I regularly raid on WoW with my 20" Al-iMac. The graphics processor usually runs at around 70-75 C (and the CPU likewise) when I do this, for several hours at a time. The aluminium case works as a very effective heat dump.

    I don't have any fan speed mods installed, since I assume that Apple's engineers are conservative, and the temperature tolerances are absolutely fine.
     
  12. Dont Hurt Me macrumors 603

    Dont Hurt Me

    Joined:
    Dec 21, 2002
    Location:
    Yahooville S.C.
    #12
    This a concern of mine also, I notice when gaming the top left of the machine gets very very hot and I never hear the fans pick up at all. I wish Apple would have included a temperature moniter and fan control within OSX. Im not sure if I can trust a 3rd party app.
    I have not seen artifacts but would feel better if I knew this thing was kicking up its fans to exhaust the extra heat.

    What fan controls are available for iMac users? are they safe? do they use up more cpu power? How about some reviews from folks using smcfancontrol? Also who wrote the program and where can you get it.
     
  13. KJmoon117 macrumors 6502a

    Joined:
    Jun 10, 2007
    Location:
    NC
    #13
    That's what I thought as well. I had my iMac since Sept-Octo ('07) and I been gaming on it (running at Apple's default temp). Now, there are moments where I see graphic errors in my dock and in my apps (dock, next to the trash).

    http://img.photobucket.com/albums/v460/DeathPalladin/Picture1.png

    Sorry for being a little off-topic here, but is my graphic chipset/card/ram damaged?
     
  14. Dont Hurt Me macrumors 603

    Dont Hurt Me

    Joined:
    Dec 21, 2002
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    Yahooville S.C.
    #14
    I installed this software 2.1 and its pretty good. the new version puts the temp & rpms on your menu bar which is cool and allows both metric and u.s. standards. Also noticed after hard gaming my old apple settings never went over 55 centigrade.Still cooler is allways bettter.
     
  15. AlexisV macrumors 68000

    AlexisV

    Joined:
    Mar 12, 2007
    Location:
    Manchester, UK
    #15
    No, Crysis and Call of Duty 4 are graphics intensive. Second Life runs on integrated GPUs, it's so graphical UN-intensive :D

    Your symptoms are of a physically faulty GPU. The GeForce 6800 in my PC two years ago died after a year, just because these things happen. There was nothing wrong with the heat disappation - it just started drawing artifacts and would lock the machine up.

    I would actually say that your post is the inaccurate one. For a start you're saying they don't have proper cooling, which is absurd. Have you not heard the fans go when things get really hot? The machine sounds like a vacuum cleaner.
    This is an extreme event though - playing Crysis for hours on end is something the machine can handle in its stride. There is nothing that needs to be 'fixed' with smcFan Control. It's merely a psychological tool because of the notion that heat reduces the life of components. Do you really think you'll be using that iMac in 8 years time?

    The top of the machine is meant to get hot. Why do you need a fan control? It's all automatically done by the EFI. The fans do go when things get intensive on a hot day, and you know about it. Other than that, the fans don't need to go to full max.

    It's a bug in Leopard after sleep. Mine does it occasionally, even when the machine is cold after just having woken up.
     
  16. Cloudane thread starter macrumors 65816

    Cloudane

    Joined:
    Aug 6, 2007
    Location:
    Sweet Apple Acres
    #16
    Erm, SL is extremely graphics intensive. It will "run" on older hardware, hell it "runs" on my G4 Powerbook, but it's unusable it's that slow. It just doesn't have any artificial limitation that says "sorry you don't have x card, quitting now"

    To me the facts are clear:

    * The flickering I was experiencing is almost always put down to heat in the PC world. And yes, Macs *are* the same chips and architecture so no "well it's not a PC" excuses :)

    * I've never heard the fans, ever, except for the test whoosh when you take it out of sleep. No matter how hard I push the machine, it just sits there getting toasty. Until installing smcfancontrol.

    * When the fans were going at a decent speed, the problems went away.

    I know for those who are incredibly loyal to Apple it may be difficult to accept that it's a result of over-conservative or faulty fan control, because that lies the blame on Apple rather than some graphics chip manufacturer. I'm not attacking Apple fwiw, they're humans, and like all humans they sometimes mess up.

    Anyway I'm glad people are playing it safe. I can't see the app doing any harm as it just speeds up fans, though I wouldn't run them at max all the time as it's bound to wear them out after a while.
     
  17. AlexisV macrumors 68000

    AlexisV

    Joined:
    Mar 12, 2007
    Location:
    Manchester, UK
    #17
    Are you kidding? It's got low system requirements, low res textures and looks like something from 1999. I don't understand your point that because it runs badly on an ancient G4, it's somehow cutting edge?

    Since the rest of us can run intensive games from 2007 for hours on end with no ill effects, and you can't run a game that runs on a GeForce2 without problems, I'd really suggest you take your Mac back to the store before it's too late. Instead of getting your problem fixed, it sounds like you'd rather sit back and suffer, declaring that you're having problems because Apple have designed their machine wrongly. You're shooting yourself in the foot with that one!

    Which just suggests you have a faulty machine.

    Well I'm not blaming the design, I'm blaming the person or machinery who put together your machine. An over the top application of thermal paste, or a heatsink that's not quite flush would probably cause the overheating problems you're experiencing.

    And now your happy to live with what sounds like a faulty machine AND stress yourself over fan speeds for fear of wearing out an expensive machine you paid a lot of your hard earned money for.
     
  18. vtprinz macrumors 6502

    Joined:
    Nov 30, 2004
    #18
    My my, let's calm down a bit, shall we? Nothing in my post deified Apple. The way I read it, you were saying that Apple had a faulty design in the way the fans work. My viewpoint was that your complaint about the iMac not handling heavy gaming well is like someone buying a minivan and expecting it win drag races. Why should it handle heavy gaming at the default settings? It's not designed or advertised to do such. It's no different, as I alluded to earlier, than someone buying a "general use" PC and having to put a stronger fan in it for gaming. If it's an actual fault in your fans, then I apologize for misreading the post, but otherwise, I'm not trying to say that Apple can't be wrong (I think they're wrong on a lot of things right now), I'm just trying to say that your complaint is unjustified (in my opinion).
     
  19. AlexisV macrumors 68000

    AlexisV

    Joined:
    Mar 12, 2007
    Location:
    Manchester, UK
    #19
    Eh? It's a £900 computer. It's designed to run any program at all, whether it's the most demanding game available, or Microsoft Word, for days on end.

    There is no 'general use' PC. Any computer you buy has enough cooling to perform similarly well, or else it's not fit for purpose. No computer on earth comes with cooling not adequate for gaming, or a disclaimer saying it can't cope with it.
    It's only when you build one yourself, or intend to overclock, that extra cooling becomes a possible consideration.
     
  20. Caris macrumors 6502a

    Caris

    Joined:
    Sep 25, 2006
    Location:
    Newcastle Upon Tyne, UK
    #20
    i thought SMC Fan Control was only for Macbooks, is it ok to use it on iMacs? Like the minimum fan speeds which is set on them is fine for iMacs so you can't turn the fans too low?

    Also if the case was overheating why didn't the iMac fans speed up?
     
  21. vtprinz macrumors 6502

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    Nov 30, 2004
    #21
    Fair enough.
     
  22. KJmoon117 macrumors 6502a

    Joined:
    Jun 10, 2007
    Location:
    NC
    #22
    The new smcFanControl (2.x) works on all intel Macs and you can't set the fan speed under what Apple had designed.

    As for the fans speeding up, I had my GPU hit high 60ºC (HDD Bay 1 high 50ºC) and the fans didn't really make any noise. The Alu encasing naturally makes a good heat sink.

    I run smcFanControl now =D
     
  23. Leon Kowalski macrumors 6502a

    Leon Kowalski

    Joined:
    Sep 20, 2007
    Location:
    Gondwanaland Reunification Front HQ
    #23
    It should handle anything with no user settings/adjustments of any kind.
    That's why Apple installed three software-controlled variable-speed fans
    and about a dozen temperature sensors. The firmware is supposed to
    continuously monitor the internal temperatures and adjust the fan speeds
    automatically.

    ...the problem is, many iMacs don't seem to be doing that,

    LK
     
  24. durija macrumors 6502

    Joined:
    Jan 16, 2008
    Location:
    Seattle
    #24
    Maybe I don't need this stuff, but I have installed and run Temperature Monitor and smcFanControl on my iMac. There are no apparent problems so far. And I must say that being able to see all those temperature readouts and then actually being able to adjust the fans to control them has given me some peace of mind. Sometimes a security blanket can make a difference in your computing quality of life. Relaxing now.
     
  25. AlexisV macrumors 68000

    AlexisV

    Joined:
    Mar 12, 2007
    Location:
    Manchester, UK
    #25
    They seem to have two settings - normal and 'emergency cooldown'.

    You'll see the cooldown phase when it's under full load, in a very hot room with the sun shining on it for example. I've only seen it once, last year. The fans come on for about 3 minutes and it sounds like a vacuum cleaner.
     

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