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Ollifi

macrumors regular
Original poster
Jun 30, 2013
180
12
After getting a 4K display (which is plugged via usb-c dock), the fans of my MBP start running at highest speed possible when I play a 1080p video from YouTube. Computer also gets warm and the video doesn't play smoothly. This issue does not occur on Safari, but occurs on Chrome and Firefox. I have tried disabling hardware acceleration without success. Any advice? Thanks a lot.

MBP 13" 2017 TB
RAM: 16 GB
the entry-level i5 CPU
latest updates installed
 
If your MBPro is getting warm/hot, you should expect the fans to run.
The fan's purpose in life is to cool down your MBPro, when necessary.
That's completely normal.
If that is an issue for you, use an app that doesn't need so much from your system.
And, for your system, with youtube, sounds like you already know that Safari is a better choice.
 
Yes, I understand that. But playing a 1080p (!) is a normal task which I wouldn't expect to stress computer so much that the fans start spinning. In my opinion for video editing fan spinning would be okay.

I prefer Safari on my iPhone but not on my Mac as the extension availability is limited and the 4K video playing is not supported.

Is there any other way to avoid the fan spinning?
 
Set it on an ice block?

Disabling hardware acceleration would only make it worse.
 
I tried playing a 1080p video on VLC. Same issue there. With 1080p monitor, no issues, but 4K monitor immediately causes the issue. Is it really true that $2K+ computer cannot handle even one 4K monitor?
 
I can play 4k video with no issues on my 2016 MacBook Pro. I can also play 1080p videos on a 4k external monitor with no problems on the same machine. 30fps either way.
Perhaps you should try another codec.
 
Thanks for the comments! I tried IINA too, and same issue there. Can you try running 60 hz mode, I have it now?
 
I think if you watch your Activity Monitor, you will note that as more CPU is used, the fan also spins up.
You will have a problem if your system heats up without the fan also spinning up.
 
Yeah, that's clear to me. But the issue is why the system heats so much that fans start spinning when playing just a normal 1080p video on a 4K screen?
 
Yes, that's probably the reason. I should probably try the 30hz mode if that'd be easier for the CPU (for robvas it seems to run normally?), however the menu to choose refresh rate is disabled. But I still feel disappointed as Apple advertises MBP for being able to run up to two 4K displays. The experience would be even worse then.
 
There is some decoding work for the system to do, and with 4K it needs to process 4 times the amount of data to construct each frame. More work, more heat, more fan speed to dissipate the heat.
 
Yep. I just wonder why I've read so little complaints about this issue. Apple sells LG's 4K & 5K monitors, I think they've the same issue so I'd expect to see more comments.
 
Yep. I just wonder why I've read so little complaints about this issue. Apple sells LG's 4K & 5K monitors, I think they've the same issue so I'd expect to see more comments.

I assume most users just run the default Safari browser which seems to be optimized for the Mac and their GPUs and thus do not generate as much heat.
 
Yeah, that's clear to me. But the issue is why the system heats so much that fans start spinning when playing just a normal 1080p video on a 4K screen?
IF you use it, it gets warm. There's nothing wrong with the fans coming on. Haven't you used other laptops where they shoot a ton of heat out of the side?
 
jerryk, yes, there's a point.

robvas, I've used MBA and currently MBP with their built-in display and external 1080p display. I have played 1080p, 4K and have not experienced choppy video playback or fan spinning like I do with the 4K display. Like I said, I accept fan spinning when I'm doing something which really requires "effort" from the computer like exporting video in iMovie. I feel playing a 1080p (or even 4K) video shouldn't require that much effort so the fan spinning surprised me.

And yes, I have heard many Windows laptops which start fan spinning much easier. That's why I've preferred Macs - I have encountered a lot less fan spinning with them. I think it's due to the OS & hardware optimization.

Fans coming on is a problem for me, since with buying a laptop, I expect it to be silent (expect certain use cases like video exporting).
 
After getting a 4K display (which is plugged via usb-c dock), the fans of my MBP start running at highest speed possible when I play a 1080p video from YouTube. Computer also gets warm and the video doesn't play smoothly. This issue does not occur on Safari, but occurs on Chrome and Firefox. I have tried disabling hardware acceleration without success. Any advice? Thanks a lot.

MBP 13" 2017 TB
RAM: 16 GB
the entry-level i5 CPU
latest updates installed

Sure you're not getting a 4K video with the 4K screen? You'd be getting VP9 encoded video, which Apple for some anti competitive reason won't support for hardware acceleration (even though the hardware is able to it). It tries to CPU decode it in chrome/firefox. Safari get limited to 1080 h264 codec, therefore no issues.
 
jerryk, yes, there's a point.

robvas, I've used MBA and currently MBP with their built-in display and external 1080p display. I have played 1080p, 4K and have not experienced choppy video playback or fan spinning like I do with the 4K display. Like I said, I accept fan spinning when I'm doing something which really requires "effort" from the computer like exporting video in iMovie. I feel playing a 1080p (or even 4K) video shouldn't require that much effort so the fan spinning surprised me.

And yes, I have heard many Windows laptops which start fan spinning much easier. That's why I've preferred Macs - I have encountered a lot less fan spinning with them. I think it's due to the OS & hardware optimization.

Fans coming on is a problem for me, since with buying a laptop, I expect it to be silent (expect certain use cases like video exporting).

If you want near silent use, why would you buy a laptop that is by design thermally constrained? All laptops make compromises on heat control its the nature of laptops and all of them will spin up fans and get hot under load (despite what you think running a 4K screen is going to put any laptop under thermal load and the smaller and slimmer that computer is the less heat management it will have) using poorly optimised for mac apps like chrome and firefox only increases this load.

If you want a near silent machine then buy a mac pro or a liquid cooled desktop PC (and the imac pro has been getting rave reviews on its cooling and ability to stay silent under load).
 
Ries, thanks for the tip. I've tried with 1080p videos only. I tried disabling vp9 with h264ify Chrome plug in, and the CPU temp still climbs to 71 °C when running YouTube in full screen mode. Also, the YouTube UI starts blinking (the bottom bar, the quality selection etc.) and the video doesn't play smoothly.

Samuelsan2001, I wanted to buy a laptop as I need a portable machine too. I think desktop machine is fine for gaming and intense 4K video editing. I dont't do those, even Apple advertises that this machine is fully capable for that. I would just like to do basic video watching with a 4K screen without computer heating so much.
 
After getting a 4K display (which is plugged via usb-c dock), the fans of my MBP start running at highest speed possible when I play a 1080p video from YouTube. Computer also gets warm and the video doesn't play smoothly. This issue does not occur on Safari, but occurs on Chrome and Firefox. I have tried disabling hardware acceleration without success. Any advice? Thanks a lot.

MBP 13" 2017 TB
RAM: 16 GB
the entry-level i5 CPU
latest updates installed


did you seriously expect a modern MacBook "Pro" to be able to play youtube at 1080p?

well - my handheld smarrtphone can play youtube at 1080p and doesn't need a fan
my 5+ year old £500 Thinkpad can play 1080p youtube on a 4k display without breaking a sweat.

but it seems anything beyond Facebook and email is beyond the MacBook Pro.
 
did you seriously expect a modern MacBook "Pro" to be able to play youtube at 1080p?

well - my handheld smarrtphone can play youtube at 1080p and doesn't need a fan
my 5+ year old £500 Thinkpad can play 1080p youtube on a 4k display without breaking a sweat.

but it seems anything beyond Facebook and email is beyond the MacBook Pro.

Yes you got the point... $2k+ machine should be able to do this but it seems it can't. Perhaps I gotta take it for a warranty repair
 
Yes you got the point... $2k+ machine should be able to do this but it seems it can't. Perhaps I gotta take it for a warranty repair

I had to take legal action against apple to get my money back.

Warranty is a time bomb. Will you be paying £700 every 3 months after your warranty is out?
 
jerryk, yes, there's a point.

I don't think you are understanding my point. Safari is optimized to use the components on the Mac and thus do not use as much power and generate as much heat and cause the fans to run. Firefox and Chrome are not. If you only have the problem with Firefox and Chrome then you need to direct your question to Mozilla and Google.
 
I don't think you are understanding my point. Safari is optimized to use the components on the Mac and thus do not use as much power and generate as much heat and cause the fans to run. Firefox and Chrome are not. If you only have the problem with Firefox and Chrome then you need to direct your question to Mozilla and Google.

for me it happened with Safari - I have recorded video evidence of this on my thread
 
I don't think you are understanding my point. Safari is optimized to use the components on the Mac and thus do not use as much power and generate as much heat and cause the fans to run. Firefox and Chrome are not. If you only have the problem with Firefox and Chrome then you need to direct your question to Mozilla and Google.

Yes, I know that. But according to comments in this thread some are not having this problem and some are not. So there are multiple possible causes.
 
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