How long is safe to run Handbrake?

divergirl

macrumors regular
Original poster
Oct 30, 2012
118
24
I have a ninth-month-old refurbished 2014 fully-specced out retina 5K iMac and I have never pushed the machine to its limits before, but yesterday I ran handbrake for about sixteen hours and I think I may have fried something.

I was also using YouTube on safari at the time this all happened, so maybe that's what did it in, but all of a sudden my screen turned foggy and was ghosting all over the place. I was seeing after images of previous images and windows appeared translucent. I tried a reboot but the issue remained. As my computer slowly cooled down the ghosting improved but I shut it down for four hours and rebooted and it's still slightly visible on the log-in screen.

I later installed istat and ran Handbrake again and it looks like the CPU runs at about 98°C/208°F while Habdbrake is running.

This is the first time I have EVER pushed my machine. Luckily I bought AppleCare for it, so I'm sure I can get it fixed, but I do plan to use premiere pro on this machine and maybe handbrake again in the future. How long can I safely run it without frying my machine again after it is repaired/replaced? :(
 

Attachments

Last edited:

h9826790

macrumors G5
Apr 3, 2014
12,768
5,579
Hong Kong
It's hard to burn the CPU, Intel really doing a good job of producing reliable CPU. On the other hand, the GPU may not be that robust.

This looks like a GPU failure more than a CPU problem to me. And Handbrake should not tax your GPU (lots of us hope that can happen, but still no reliable OpenCL solution for Handbrake yet).

It may be just a coincident. Or may be the 16 hours radiating heat from the CPU damage some other electronics next to the CPU. Or simply you get a faulty GPU. By the way, Apple will fix it for you.

If you want to avoid over stressing the machine, you may limit Handbrake by command "threads=(number as you wish)". This will limit Handbrake can only use up to the number of thread that you allocated to it.

e.g. In my case. I have a Hex cores (12 threads) CPU, and I limit Handbrake can only use up to 8 threads, which will leave me 4 threads for other stuff. So that I can leave Handbrake in the background 24/7 and I won't feel any slow down in the foreground. And the good side effect is that this will make the CPU run a bit cooler.
Screen Shot 2016-05-01 at 01.21.59.jpg

I don't know if it's useful to you. But you may consider something like thread=6 for your i7. Don't expect any large difference in temperature, it may only help a little bit.

On the other hand, if your fan is not running in full speed yet, you may consider use MacsFanControl to customise a fan profile which is more sensitive to the CPU temperature. (Caution: Be careful, AFAIK, there is only one fan in your iMac to cool both CPU and GPU. If you make the fan speed purely base on the CPU temperature, that may adversely reduce cooling to the GPU. A more safe way to do it is manually fix the fan speed at max when you expect that you will stress your CPU or GPU.)

By combining these 2 methods, hopefully your machines will run few degrees cooler, and that can make huge difference if the electronics around is actually operate right at their thermal limit.
 

joema2

macrumors 68000
Sep 3, 2013
1,579
787
...This is the first time I have EVER pushed my machine. Luckily I bought AppleCare for it, so I'm sure I can get it fixed, but I do plan to use premiere pro on this machine and maybe handbrake again in the future. How long can I safely run it without frying my machine again after it is repaired/replaced? :(
This is not the fault of HandBrake or any other software. You should not have to adopt elaborate procedures in a speculative attempt to avoid things like this. What if you were rendering a big project in Premiere? Are you not supposed to do that? Should you be be forced to use some special utility to limit CPU or GPU consumption? If so how could you possibly be expected to know that? Where is it documented? (It's not).

Some professional editors working on Deadpool using Premiere CC were doing intensive rendering on New Mac Pros and supposedly had some GPU failures. It was not the fault of Premiere or their procedures. The hardware just failed. It could have been a manufacturing glitch with thermal compound, assembly or anything.
 

accentaudio

macrumors 6502
Apr 4, 2012
359
108
Kansas City
Last edited:

MBHockey

macrumors 68040
Oct 4, 2003
3,927
161
New York
You have what Apple calls "image persistence" and a bad case of it at that! Boy oh boy, this really concerns me that they still haven't fixed this problem.

See the following thread:
http://forums.macrumors.com/threads/just-ordered-the-big-one-please-no-image-persistence-issues.1969089/

And go here:
https://support.apple.com/en-us/HT202580

You need to report this to Apple so their engineers can see it. I would include your photos as well.
it's a 2014 machine
 

MBHockey

macrumors 68040
Oct 4, 2003
3,927
161
New York
And...? Image persistence still occurs on 2014 machines. It is not year specific.
My comment was in response to your concern about it still being an issue. From what I remember, this was always an issue on the 2014 machines and not so much on the 2015 ones.
 

accentaudio

macrumors 6502
Apr 4, 2012
359
108
Kansas City
My comment was in response to your concern about it still being an issue. From what I remember, this was always an issue on the 2014 machines and not so much on the 2015 ones.
Ahhh ok. Makes sense. Well I hope they have fixed it on 2015 machines. I'll know tomorrow. ;)
 

T Coma

macrumors 6502
Dec 3, 2015
284
512
Flyover Country, USA
Wow, that is running hot. I never checked my temps, but I've been handbraking 100s of hours of HD traffic videos on my 2011 27" i5 mac running Mavericks. It's still chugging along with no apparent issues - maybe I should download iStat...
 

throAU

macrumors 603
Feb 13, 2012
5,284
2,276
Perth, Western Australia
It should not be possible to deliberately kill your machine via software, especially a non-maliciously coded application.

The intel CPUs are within spec at over 100 C, and will throttle themselves down in terms of clock rate to prevent being cooked if they get too hot.

e.g.

for my i5-5287U in my 13" Retina:

http://ark.intel.com/products/84988/Intel-Core-i5-5287U-Processor-3M-Cache-up-to-3_30-GHz

T-junction is the max CPU temp allowed, and for that CPU is 105 C.

Your machine should be safe to sit on 98 degrees indefinitely.
 

accentaudio

macrumors 6502
Apr 4, 2012
359
108
Kansas City
:rolleyes:See my post where I state exactly what issue the OP is having. It's not a thermal issue. People on these threads don't really seem to read all the posts.
 

throAU

macrumors 603
Feb 13, 2012
5,284
2,276
Perth, Western Australia
:rolleyes:See my post where I state exactly what issue the OP is having. It's not a thermal issue. People on these threads don't really seem to read all the posts.
The question was "how long can i run handbrake".

Not speculating on what is or may be wrong with the machine, but handbrake should be safe to run indefinitely. If it causes problems, your hardware is broken.
 

accentaudio

macrumors 6502
Apr 4, 2012
359
108
Kansas City
The question was "how long can i run handbrake".

Not speculating on what is or may be wrong with the machine, but handbrake should be safe to run indefinitely. If it causes problems, your hardware is broken.
I was addressing the OP's real issue with their machine.