iMac High Fan Speeds And Very Bad Lag

Ok so i have got a iMac 3.2 GHz Intel Core i5 and i have recently noticed that when I'm playing Video Games via steam my fan kicks on at the highest speed and the game becomes unplayable due to lag , i don't even have to be playing a game for this to happen so i decided to wipe my HardDrive and start clean the same problem kept on happening i don't know what to do and what is happening i have reset my PRAM and i think my SMC but i don't know ,should i contact my local apple store? Also i still have my 1-year warranty if it has to be replaced

Video Games drive the CPU and GPU very hard, which generates heat. That's why the fan comes on and runs high...it's normal. Lag is probably due to the same demand. One confusing thing you said:

i don't even have to be playing a game for this to happen

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What does that mean? What are you doing when not playing a game? The one time I tried Steam, it drove my CPU pretty hard, so even when you aren't playing Steam may be pushing your CPU.

If you really want to play games, MBPs are NOT the best choice.

Actually he has an iMac. Someperson.... can you tell us which model iMac you have, as well as how much RAM you have, and how much used vs free space you have on the drive?

True, but an iMac is not a gaming machine, either.

MacInWin said:

True, but an iMac is not a gaming machine, either.

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I beg to differ. I've gamed on mine just fine. Prior to the 2009 model introduction, I would have agreed though.

I've got to agree with LAB on that... I've gamed on both of my iMacs with never a problem and I ran some fairly graphic intensive games. But let's face it, no Mac is up to par with an Alienware machine when it comes to gaming.

I think that there's at least a "semi-agreement" that Mac's aren't the best gaming computers. But they can certainly play most games very well...and only the most hardware intensive games (at max. resolutions and detail settings) is where Mac's start to have trouble.

Of course not all Mac's are "created equal" either. The higher end iMacs (with descrete graphics hardware) seem to be the best "gaming Mac's" to choose from (at least for us "mere mortals")!

The new Mac Pro I guess would be the best. But then again...I think that a SUPER Windows gaming computer could be built for at least 50% ($1500) of the price of an entry level new Mac Pro ($2999)...or less.

- Nick

2010 i3 iMacs fit the 3.2GHz bill. Any chance you have replaced the hard drive yourself or by a non-Apple technician? Apple introduced speical heat sensors in an attempt to prevent user upgrading. Doing the hard drive upgrade without the proprietary drive or sensors cause the fans to talke off like a Jumbo 747.

For you guys REALLY into the technical/hardware side of gaming. Here's a review I found regarding the "new" Mac Pro:
AnandTech | The Mac Pro Review (Late 2013)

Here's a video of a guy running SIX (6) 27" displays at 4k resolution on a new Mac Pro playing Crysis 3 (zip to 1:18 of the video to see it):
Crysis 3 on Late 2013 Mac Pro with 6 27-inch screens in over 4K resolution | 9to5Mac

And here's an article on "Can a Mac be a gaming PC?":
Can a Mac be a gaming PC? How the world is changing for Mac gamers | News | TechRadar

- Nick

harryb2448 said:

2010 i3 iMacs fit the 3.2GHz bill. Any chance you have replaced the hard drive yourself or by a non-Apple technician? Apple introduced speical heat sensors in an attempt to prevent user upgrading. Doing the hard drive upgrade without the proprietary drive or sensors cause the fans to talke off like a Jumbo 747.

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That was 2011. The 2010 models still take off-the-shelf drives, though you do have to stick to the same brand due to a thermal sensor cable having a different connector for each manufacturer. Or you can get a new cable if you want to switch to a different manufacturer's drive.

Applies for the late 2009 model if the identical drive is not used:-

How do you upgrade the hard drive in the "Late 2009," "Mid-2010," "Mid-2011" and "Late 2011" (21.5-Inch and 27-Inch) Aluminum iMac models? What type of storage do they support? Is it even possible to upgrade these models? @ EveryMac.com

8 Gb of Ram and i just got this less then a year ago near december , and i don't know what model but it think its ether 2013 or 2014 , and when i boot it up in like a min. it starts going crazy and i did not tamper with it at all is this a defective or factory reject I'm confused right here , and when I'm not playing games I'm just booting it up or just in finder it starts with the fan and framerate drops , and i have 881.06 free out of 959.35 GB so i think I'm good on disk space and ram

someperson99 said:

8 Gb of Ram and i just got this less then a year ago near december , and i don't know what model but it think its ether 2013 or 2014 , and when i boot it up in like a min. it starts going crazy and i did not tamper with it at all is this a defective or factory reject I'm confused right here , and when I'm not playing games I'm just booting it up or just in finder it starts with the fan and framerate drops , and i have 881.06 free out of 959.35 GB so i think I'm good on disk space and ram

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The framerate drops when NOT playing a game? I would love to know how you came to that conclusion. You really should be more certain of what model iMac you have here if you want more specific help. Also take note of my signature. If you have properly reset your SMC and are still having fan issues, then it's likely something is running in the background to make that happen. Or maybe you are using some 3rd party software to control the fans?

i did have smc fan control but thats before i wiped my hard drive clean , and yes i get VERY bad framerate drops , ill post a youtube video of the framerate

Take it back to the reseller or Genius Bar.

someperson99 said:

i did have smc fan control but thats before i wiped my hard drive clean , and yes i get VERY bad framerate drops , ill post a youtube video of the framerate

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Since you did have SMC Fan Control Installed, wiping the hard drive clean would have left the SMC fan settings in the wrong state unless you instructed that software to restore the settings to defaults. Wiping the hard drive would not have done so itself. If you have not done an SMC reset, you should do so.

ok, so sorry about how long it has been i have taken it to the genius bar and say said that KernalTask is taking up 300% of my CPU so something is running in the back round but i wiped the hard drive from the restore partition that comes with osx they said try updating it and i did ... no fix so i looked up instructions on youtube and it said to delete my model .plist in ioplugins or something like that it was like a week ago i can barely remember, i couldn't find my model there so i deleted all of them thinking that osx would automatically restore them to defaults if not found no fix my 1-year warranty is still not up so i can still take it back to the Apple store

Ay, caramba dude...it's been 5 months!!!

Great to hear you still have warranty remaining. A nice safety net!

- Nick