27" iMac GPU Diode Temperature?

Discussion in 'iMac' started by gmanist1000, Jul 4, 2011.

  1. macrumors 68020


    Sep 22, 2009
    I have the new 27" iMac and when checking iStat my GPU Diode temperature seems very high. It's at 187 degrees fahrenheit, sometimes when the computer is doing nothing at all.

    I have the AMD Radeon 6970M - 2GB VRAM, if that helps.

    Is this too high? Should I install SMC fan control?

    Attached Files:

  2. macrumors 601


    Feb 6, 2010
    On the fence
    Not sure about the GPU, it does seem a bit on the warm side, but it is a fairly hot part and that is within operating temps. However, that's definitely on the hot side for the HDD, so if anything I'd up that fan speed a little bit.
  3. macrumors 6502

    Feb 9, 2003
    Reset your SMC and PRAM and see if it is still that high.

    I just finished playing WoW for 4 hours and my GPU diode was at 71C (160F.)
    It's at idle at the moment and is at 48C (118.4F.)
  4. macrumors 6502

    May 15, 2011
    I have the same config, and that seems warmer than it should be. I don't think you need to install SMC fan control though - it looks like your optical drive fan has already spun up to compensate -- this is similar to what I see on my machine after I've been gaming for a few hours & the room is hot, though my GPU is more ~170deg.

    If the GPU really should be idle, I'd say its a potential problem. try the PRAM reset suggested (or a cold boot), let the machine idle for 20 minutes, and see what the temperature reads... I would expect numbers closer to your CPU temp...
  5. thread starter macrumors 68020


    Sep 22, 2009
    Thanks for all the suggestions. It is very warm where I live, it was over 93 degrees Fahrenheit outside when I took the screenshot. That may be one of the problems.
  6. macrumors 68000


    Oct 29, 2009
    You should turn on the AC.

    Have you thought about calling Applecare?
  7. macrumors regular

    Jun 29, 2010
    Mine is at 67C and I just quit playing EVE. I've seen it go into the high 80s (warm day at the time too though), so I think it's fine.
  8. thread starter macrumors 68020


    Sep 22, 2009
    If we had AC I would. I haven't called them yet, if I encounter problems I will.
  9. WazoooGuru, Jul 15, 2011
    Last edited: Aug 19, 2011

    macrumors newbie

    Jul 15, 2011
    Mine is hot, too

    I noticed the same thing a few days ago on my iMac (27" i7, 2011). My GPU temp was about 175° F with nothing running.

    After doing a few experiments, here is what I observed:
    My ambient room temp is about 77° F.

    I have a second display hooked up through the Mini-display port (20" Apple Cinema Display (ADC) via an Apple DVI to ADC Converter. When the display is plugged in, the GPU temp idles at about 170° F. When I unhook the second monitor, the temp drops to about 145° F within 4 minutes.

    I used smcFanControl to bump the Optical drive fan speed to a constant 1400rpm and the GPU temp stays at a comfortable 145° F. The GPU heatsink is above the optical drive so the air flows over it on its way out the top.
  10. macrumors 65816

    Apr 4, 2007
    los angeles
    I noticed the GPU diode was at almost 190 last night. I of course have added an SSD and swapped hard drives so I am using a fan control app.

    I woke up this morning and with screen off for 7 hours, it was down to 115.

    Good tip though, I will try increasing the ODD fan a little bit when I am using the machine.

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