Hi i just bought an iMac 5k with i7,295x and I knew that when i bought it that it would struggle to play games due to the 5k and overheat. Anytime I play World of Tanks it starts to overheat as soon as it starts and I don't want that heat next to my screen. I noticed that when I use Parallels and play the game in a smaller window about 1/3 the size of the screen my fan does not even turn on and it runs better. Is this due to less pixels being used or is it that the Parallels is using its graphics emulator? I thought about using a second monitor and then just playing games with it at a lower resolution. Is there anyway this could be done or would it still overheat at 2.5k?
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imac 5k game play questions using external monitor
- Thread starter dred67212
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Firstly, your iMac is not overheating. If it were overheating it would simply shut down. It's running hot, the fan is probably at 2300rpm and the CPU/GPU will likely be throttling slightly to keep temperatures "safe".
Parallels will be restricting the use of the CPU and GPU, so the performance will be dramatically decreased, but the load on your CPU/GPU will also be alleviated. This leads to cooler temperatures, and therefore quieter fan noise.
Adding another screen would cause even worse performance because the GPU is then powering two screens, roughly 7.5K of pixels.
You can play your games at 2560x1440p (or 2.5k) on the 5K iMac.
Edit: Out of interest, if you knew it wasn't going to satisfy your needs, why did you buy it?
Parallels will be restricting the use of the CPU and GPU, so the performance will be dramatically decreased, but the load on your CPU/GPU will also be alleviated. This leads to cooler temperatures, and therefore quieter fan noise.
Adding another screen would cause even worse performance because the GPU is then powering two screens, roughly 7.5K of pixels.
You can play your games at 2560x1440p (or 2.5k) on the 5K iMac.
Edit: Out of interest, if you knew it wasn't going to satisfy your needs, why did you buy it?
I was hoping playing on a screen that is truly only 2.5 k and not being converted with the timing controller on the 5k would help the performance.
The heat gets so bad it almost burns my hand on the back of the unit and when i touch the screen on the front it is really hot and I don't think it is good for the screen so I was looking for a way to play games without the excessive heat and fan noise. I am in my 14 day window and don't want to send it back but if a simple game set on low settings makes it this hot and loud its only really good for text, web browsing and photo editing.
The heat gets so bad it almost burns my hand on the back of the unit and when i touch the screen on the front it is really hot and I don't think it is good for the screen so I was looking for a way to play games without the excessive heat and fan noise. I am in my 14 day window and don't want to send it back but if a simple game set on low settings makes it this hot and loud its only really good for text, web browsing and photo editing.
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Indeed. There's significant discussion online about the thermal issues with this particular model. I returned my i7/M295X 5K iMac for the same reason.
Many YouTube videos prove the thermal throttling issues exist, but of course only with individual units - it would be a big assumption to say the issue exists for all units. You've seen for yourself that the issue does exist on your unit, though, which is all that matters. Whether or not you and I have just been unlucky, well...we'll never know. It sure does seem common, though.
I was told by an Apple technician that the GPU temperature I was seeing (105°C) was "not safe for anything". That was the final nail in the coffin for me. I'm waiting a few months for the next generation. My 2010 iMac with an SSD is fine for the time being.
Obviously a number of other people here have opted to keep their iMac despite being aware of the heat and throttling issues. It's your decision to make.
I would add that the majority of users here seem to recommend the upgraded 2013 iMac for gaming purposes over the 5K iMac for this very reason. The 2013 iMac certainly runs cooler, and offers very similar performance.
PS. I never noticed the back of my unit getting hot. It was always cool to the touch, even after a long gaming session with the GPU at 105°C and the CPU at 99°C.
Many YouTube videos prove the thermal throttling issues exist, but of course only with individual units - it would be a big assumption to say the issue exists for all units. You've seen for yourself that the issue does exist on your unit, though, which is all that matters. Whether or not you and I have just been unlucky, well...we'll never know. It sure does seem common, though.
I was told by an Apple technician that the GPU temperature I was seeing (105°C) was "not safe for anything". That was the final nail in the coffin for me. I'm waiting a few months for the next generation. My 2010 iMac with an SSD is fine for the time being.
Obviously a number of other people here have opted to keep their iMac despite being aware of the heat and throttling issues. It's your decision to make.
I would add that the majority of users here seem to recommend the upgraded 2013 iMac for gaming purposes over the 5K iMac for this very reason. The 2013 iMac certainly runs cooler, and offers very similar performance.
PS. I never noticed the back of my unit getting hot. It was always cool to the touch, even after a long gaming session with the GPU at 105°C and the CPU at 99°C.
I like the retina screen. I will have a hard time going back to a regular screen after this and would like to find a way to make it work. If only it had a better way to cool itself I think it would be a great machine. I think they should of added vents to the top so the heat could flow out the top as well as the back like the 2011 iMacs.
Maybe someone can make a aftermarket ram door with vents and a larger slow rpm fan, but that prob wouldn't do much if anything. Maybe if it lowered it 3 degrees it might.
Also if someone could figure out how to put the 5k monitor to sleep while playing high demand games on a lower res second monitor it should in theory dramatically lower the load on the gpu and the 295x should easily be able to handle the old 2.5k res without getting that hot.
Maybe someone can make a aftermarket ram door with vents and a larger slow rpm fan, but that prob wouldn't do much if anything. Maybe if it lowered it 3 degrees it might.
Also if someone could figure out how to put the 5k monitor to sleep while playing high demand games on a lower res second monitor it should in theory dramatically lower the load on the gpu and the 295x should easily be able to handle the old 2.5k res without getting that hot.
This is a personal opinion, obviously, but look at the way this discussion is going...
We are actually searching for ways to turn off the screen of an all-in-one computer. That just screams 'wrong product' to me. The 5K iMac is not the solution for your needs if you're looking to disable its primary display and run a 2.5k screen instead.
Buy a Mac Pro for very GPU intensive professional work or, for gaming, a Windows gaming rig.
We are actually searching for ways to turn off the screen of an all-in-one computer. That just screams 'wrong product' to me. The 5K iMac is not the solution for your needs if you're looking to disable its primary display and run a 2.5k screen instead.
Buy a Mac Pro for very GPU intensive professional work or, for gaming, a Windows gaming rig.
I have a second screen (2048x1152) and I can use both for playing (but I keep using the main for obvious reason), if you are not doing anything complex in the main one you are not stressing the GPU more than with that monitor turned off, using games in a lower res monitor you will reduce the load significantly.
Running a game at 1440p on a 5K screen should give near-identical performance to running a game at 1440p on a 1440p screen with the same hardware.
As such, if the OP buys another 1440p screen to run games on, they are decreasing performance because the GPU is running a game at 1440p on and the 5K screen. Whereas if they just run the game at 1440p on the 5K screen with no external display, they will get optimal 1440p performance.
In short; a 5K iMac running a game on a 1440p monitor will offer worse or equal gaming performance than simply a 5K iMac running at 1440p.
The performance are identical, but at 1440p the scaling is not that good, you lose sharpness, a native 1440p will give you better result, at 4K it's still decent but low difference in GPU lo ad.
But my advice is to stay on 5K and lower the detail, the gpu will run cooler and you gain also more fps without wasting money for an additional monitor.
I am curious if there would be any difference by having the gpu not have to talk to the 5k timing controller and just exporting graphics to a lower res non 5k tcon screen. I don't know much about how it works. If anyone has the extra monitor and 5k iMac i would love to know the results.
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Hmm, like a 500hp car that has to be kept under 60mph or it overheats.
Some irony.
Interesting 5K news coming
Re-reading I'm thinking that if it overheats that bad it will do more or less the same even at lower resolution, if you don't have it, buy Apple Care and keep going with the main display 
I'm still shocked by how much difference there are between RiMac, the chassis of mine is cold, and for cold I mean it, even after 3-4 hours of gaming.
I'm still shocked by how much difference there are between RiMac, the chassis of mine is cold, and for cold I mean it, even after 3-4 hours of gaming.