New iMac user and I have a couple of questions...

[ozziegn]

I decided to try the new M3 iMac mainly because I'm relying on my 28" external monitor more and more. I have a 15" MacBook Air that's my secondary monitor but its looking pretty small to my 55 year old eyes more and more. So I just picked up an iMac with 16/512 specs. I have always used TG Pro on my laptops to monitor CPU temps mainly and I just installed it on my iMac.

First question is what are typical CPU idle temps on these machines? My M2 MacBook Airs idled around the 40C area but I'm surprised to see how much warmer the M3 runs at a typical 62C. Is this right? And if so, what is considered dangerous in terms of CPU temps? I was installing a couple programs and my temps pegged to like 105C which I thought was crazy. Of course I don't know which is why I'm asking here.

Second question is do most of your guys and gals just let your iMacs go to sleep or fully turn them off when not being used?

Thanks for any info and advice.

 

[RUGERMAN]

I decided to try the new M3 iMac mainly because I'm relying on my 28" external monitor more and more. I have a 15" MacBook Air that's my secondary monitor but its looking pretty small to my 55 year old eyes more and more. So I just picked up an iMac with 16/512 specs. I have always used TG Pro on my laptops to monitor CPU temps mainly and I just installed it on my iMac.

First question is what are typical CPU idle temps on these machines? My M2 MacBook Airs idled around the 40C area but I'm surprised to see how much warmer the M3 runs at a typical 62C. Is this right? And if so, what is considered dangerous in terms of CPU temps? I was installing a couple programs and my temps pegged to like 105C which I thought was crazy. Of course I don't know which is why I'm asking here.

Second question is do most of your guys and gals just let your iMacs go to sleep or fully turn them off when not being used?

Thanks for any info and advice.

I just retired a 2010 iMac that I never turned off and was running fine, my wife had a 2017 MB air and now has a 3 yr old mi air all the same thing. Never turned off, no problems.

 

[kagharaht]

I have a 24/2TB. Idle is at 93F or 33C. I don't anything difficult anymore but I played with Handbrake to see how fast it can run a conversion. Did an 11 min MKV 1080P to Apple TV. Using H265 video toolbox 10 bit. It ran a temperature range of 110 120F or 48C. Goes up and down as the fan cools it. I haven't turned it off since a user posted less than 5W idle screen off. Sleep he said -1W! Amazing. I may start doing sleep instead. I leave it on never turn it off because we use Home Sharing to connect to the iMac. My initial test shows it's pretty instant even in sleep mode! Anyway I never turn it off. I used MenuMeters so I have no idea how accurate it is but that's what I got.

 

[Jackbequickly]

Yep, my M3 is only using 1 watt while asleep and yet it is still listening for Hey Siri. Exceptional!

 

[Andrey84]

I don't know the idle/maximum temperature for M3 specifically, and I was unable to find it in Google.

However, I do know these things:

1. My my wife's Intel iMac idles at 62C. It frequently goes up to 90C under heavy load.
2. My Intel MacBook Pro idles at 42C, so, also 20 degree difference.
3. With Intel CPUs maximum allowed temperature is 100C.
4. Intel CPUs have a built-in overheating protection, independent of the OS, which throttles them down until the temperature drops below 100C.

So, assuming Apple M3 is the same, you should not worry in general. However, let's see what other iMac owners post.

There is absolutely no need to turn your iMac off, just let it sleep as per Settings.

 

[ger19]

There is absolutely no need to turn your iMac off, just let it sleep as per Settings.

I always thought it was a good practice to turn it off once in a while. Not sure why, but I guess I thought it was good to clear cashes and reboot various system programs. Nothing like that going on???

 

[Andrey84]

I always thought it was a good practice to turn it off once in a while. Not sure why, but I guess I thought it was good to clear cashes and reboot various system programs. Nothing like that going on???

Of course, you need to reboot once every 2-6 weeks, depending on your usage. However, this is normally covered when the system asks you to reboot to install a new security update!