iMac Retina 5K with M295X GPU - is it noisy?

MiJMac wrote:

My experience, so far, has been silence regardless of what the iMac is doing. I have played HD YouTube and Netflix full screen without any noticeable noise. As I noted before, the machine is also exceptionally cool, only slightly warm, to the touch (much cooler than my 2009 era iMac) so the processor (both i7 and GPU) temps must be reasonable. I have only had it for about 8 days so still more to discover, but so far no complaints. I'll play with it some more this weekend and report if my experience changes.

That's strange. I've heard so many people with that configuration saying that the fans ramp up for very little. Is it possible that your ambient noise exceeds the noise of the iMac?
Could you possibly get a reading of your fan speed and temperatures? Perhaps play a little with the app CPU Test to see how it reacts to that.

That it's cooler to the touch than your 2009 model is not surprising since that case picked up a lot more heat than the new ones does. It says nothing about how cool the computer is running on the inside. The cooling system works a bit different in those.

It does seem I have a machine that is an outlier to what I see posted. My environment and the ambient noise is very quiet/nil, but then maybe I'm too old to notice. I should have some time over the weekend to stress it, do what you suggest and find if my perception changes. I also have a sound level meter (dB SPL) that I could use to get some objective measurements instead of relying on my hearing.

MiJMac wrote:

It does seem I have a machine that is an outlier to what I see posted. My environment and the ambient noise is very quiet/nil, but then maybe I'm too old to notice. I should have some time over the weekend to stress it, do what you suggest and find if my perception changes. I also have a sound level meter (dB SPL) that I could use to get some objective measurements instead of relying on my hearing.

That would be very interesting! Just as long as it doesn't take the pleasant experience away from you 🙂

It is indeed subjective. Some think the same level of noise is pleasantly quiet while others consider it annoying, which can make reading forum posts on the subject a bit confusing. That's why I'm more interested in actual sensor readings.

I wish there was a standard benchmark app for measuring thermal sensors, throttling and fan speed during different kinds of loads. To me that is just as important as any other benchmark and I'm surprised that reviewers rarely write about these subjects.

That's the configuration which interests me too (better CPU, but base GPU).

How smooth are the animations with Mission Control or with large image previews in Finder?

There are reports that both lag a bit for the baseline model...

I am wondering whether the cause is software, the GPU or the CPU/RAM...

Nicely maxed-out machine!

Do you experience lag in Mission Control as posted by some other 5K iMac users (e.g. here: mission control imac retina) ?

Many have posted lag, stutter in transitions, judder in opening/expanding screens and applications. I have experienced none of these. Granted I have no experience with a base machine and can't speak to the performance of an i5 iMac with 27-inch Retina. Unfortunately I do not know if the CPU, GPU or less than 32 GB memory is responsible. I can say that I have zero complaints with the performance of the iMac I have.

I'm sorry but the i7 with m295x is loud while gaming or rendering etc. where cpu and gpu is used.

I've measured heat and fan speed now for 2 weeks. here's my results:

- any game will make the fan blow after 1-2 minutes to 2300-2700 rpm which is between 35-38 db. gpu temp is between 100 and 107 C!

- light activity like youtube, photoshop, iphoto, browsing etc. will have no impact.

if you're a gamer like me it's a disappointment. check forums which either report throttling of more than 50% (half the fps) or excessive fan noise (no throttling), e.g. with world of warcraft.

Yes, there are a lot of people complaining about throttling, overheating, etc. of the 295X. The suggestion is that it will burn out.

Surely Apple must have torture tested the 295X in demanding games, etc.

i7 295x with 8gb ram here and i get loud fan with multiple videos opened or when i batch edit in lightroom. pretty annoying tbh

I have had a few days now to spend with the new machine. I have not done heavy testing, but casual usage during the day. Note: no gaming so far.

My initial concerns have largely been unfounded. I have had no complaints watching youtube in any resolution any more. I was afraid the new 60fps mode would be too taxing and cause the fan to go crazy, but it seems that is not the case. What I suspect is that, on my first day of setup of the new imac, I had a few other tasks running at the time I was watching YT and the noise became an issue. Notably, Dropbox was synching a large amount of data in the background. I find it curious that this would be so taxing as to cause the noise/fan issue, but maybe it's just that.

After this first day, I have not heard the fan once. Given, I have not been doing very CPU/GPU-intensive work, but watching videos does not cause the same issues it caused on that first day any more, which is good. I have also watched some 1080p content in VLC. Didn't make any difference, the fans were quiet.

I will be closely monitoring the fan noise for now, especially when I get to play some games on the machine, but – for now at least – I'm not totally disappointed any more. Hardcore gaming has never been the focus of Mac computers, so I'm used to taking a few performance hits there, be it hardware or software. Maybe they can also fix a few things with firmware updates in the coming months, to improve a little. If I find out something new, I'll report back. For now I'd say it's still an awesome machine and a great fit for light and medium usage.

Install Turbo Boost Switcher and deactivate turbo boost, it always had worked in every mac I had problems with fans. Turbo Boost seem to be a extremely bad implemented tech in macs. Here you can download it (download the free one):

http://tbswitcher.rugarciap.com/

I have two maxed out iMac 5Ks. One with only 16gb ram.

So far whisper quiet and very cool to the touch.

Seems there are experiences from both ends of the spectrum. Another thread mentioned someone took their iMac to the Apple Store to have it checked and the firmware was suspected. I wonder if there are different firmware versions responsible for the both the loud fans and the opposite. Worth investigating as I'm certain there are rolling updates even during this early delivery/assembly of the iMac and the firmware version differences could resolve the high-speed fan problems some are reporting. Personally I am on the quiet iMac side no matter how I have used the machine.

don't fool yourself. there are no differences in mass production only reason fan is no issue for some is because those people don't use cpu/gpu intensive tasks and only browse the web or do photoshop.

I've yet to read from anybody that a handbrake session with the i7 didn't bring the fan to 2700 rpm after 2 minutes or playing wow with the m295x didn't heat up the gpu diode to 105C and bring the fan to 2700 rpm after 2-3 minutes.

It's _very_ noisy as soon as the graphics card fires up, which it will do in every game. I've played games both in OS X and Win8.1 and it's (obviously) the same.

The fan on my iMac 5k (295X i7) has also started to make a "flappy" ambient sound as well from last night and going. Very annoying for such an expensive device.