2019 Sensitive fans or processor stress running Handbrake?

golfgirlgolf

macrumors member
Original poster
I've just moved to a 2019 3.7 6 Core - from a 2015 3.3GHz, Quad Core

Running Handbrake video conversion I never used to get the previous iMac's fans running on high at all - but the 2019 one does. Somehow I thought it would/should have been the opposite. Activity Monitor reported 400-500% CPU. Temp monitor said about 110 degrees F but I need a better tool for this.

It's not something I do very often so I'm not overly concerned about too much heat too often. But I was very surprised. Should a 3.7 2019 get stressed out so easily - or have they just made the fans come on faster?

Edit - I also just had fans running when exporting 30 downsized JPG files out of Lightroom - which should be a really lightweight task. hmmmm
 
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priitv8

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PBMB

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Mar 19, 2015
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I've just moved to a 2019 3.7 6 Core - from a 2015 3.3GHz, Quad Core

Running Handbrake video conversion I never used to get the previous iMac's fans running on high at all - but the 2019 one does. Somehow I thought it would/should have been the opposite. Activity Monitor reported 400-500% CPU. Temp monitor said about 110 degrees F but I need a better tool for this.
Does this happen with a precise video or is it general?

You can also post a link with a video to download and to process, as well as the list of Handbrake settings so that other forum members here can test it.
 

golfgirlgolf

macrumors member
Original poster
Thanks for the replies and also the link to the Intel tool - very good!

This is happening in general. I've tried several different versions of HB - and a couple of kinds of input and output.
I first ran into it trying the newer H265 2160p60 Apple TV 4K HEVC output.
Then went to test Apple 1080p60 H264 which I've been using for years. Same.

It's happening in general. I started testing with larger ISO files (feature film type video TS) - but tested again with a simple 1GB QuickTime .mov file -> H264. Same thing... see screenshot. This should be a lightweight task IMO.

More disturbing however is the Lightroom exporting which I do regularly. A tiny run of outputting (30) 2000px JPG proofs shouldn't tax the system. It's going to go crazy when I hit it with hundreds of 8000px full resolution files! Fans never came on once before with these tasks.

I thought I was upgrading my 2015 iMac - but the blowing fans make it feel almost like a downgrade. :-(

I suppose the explanation could be - more horsepower - hotter processor = fans. It somehow just doesn't feel "right" though.

Screen Shot 2019-06-20 at 8.27.46 AM.png

[doublepost=1561037376][/doublepost]Here's a downloadable link to a little 1GB .mov file that causes the fans to come one - test if you like....

https://drive.google.com/open?id=19CJPsHYEgdSOCB8rKDC5JKwzd7ZHWWDd
 

kohlson

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Apr 23, 2010
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Handbrake is considered to be a benchmark comparison measure, but it does pretty well at utilizing all available CPU resources. If you open up Activity Monitor you can watch for yourself. Doesn't really matter what types of files it's converting from/to - it just tries to complete the conversion as quickly as it can.

In general, every generation CPU has more processing capability. But depending on the manufacturing process (such as transistor size, like 14 nm), some CPUs have different thermal characteristics, such as heating up more or less than previous generations. There are lots of factors at play here.

If you're only occasionally getting the fans to spin up (like a couple of times a day) I wouldn't worry about it.
 
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PBMB

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Mar 19, 2015
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I suppose the explanation could be - more horsepower - hotter processor = fans. It somehow just doesn't feel "right" though.
Perhaps, I am not sure.

Here are my results. I tried to convert a 4.7 GB DVD using Handbrake to device "Apple 1080p30 Surround" (I don't see the device options you posted previously; I guess the Handbrake version may just be different). Conversion completed in about 7 minutes, the fan was clearly audible but not intrusive, CPU (all 6 cores of the i5-9600K) at 97-99% and 4.0-4.1 GHz, while the temperature was hovering between 92 and 96ºC. I don't know it that matters, but I have a 512 GB SSD, 40 GB RAM and the Vega 48.
 

priitv8

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Jan 13, 2011
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It's happening in general. I started testing with larger ISO files (feature film type video TS) - but tested again with a simple 1GB QuickTime .mov file -> H264. Same thing... see screenshot. This should be a lightweight task IMO.
HandBrake encode is never a lightweight task!
First - it is always a full re-encode (never just a remux of a stream into new container).
Second - it always loads all available CPU cores and threads to the max.
On a more performant CPU you are just supposed to finish in shorter time.
The only exception to the above is the VideoToolbox variety of encode - this one uses Intel Quick Sync technology - ie the hardware encoder on the chip.
Screenshot 2019-06-21 at 00.27.44.png
Can not comment on lightroom - don't use it.
 

PBMB

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Mar 19, 2015
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The only exception to the above is the VideoToolbox variety of encode - this one uses Intel Quick Sync technology - ie the hardware encoder on the chip.
View attachment 844150
I was not aware about this. I tried with that setting for the encoder and the conversion time was cut at half with no fan noise at all! :eek: CPU temperature at 82-88ºC, utilisation 65-70% at 3.5-4.0 GHz. But there was another CPU coming into play, one named "GFX" by Power Gadget at ~1.0 GHz and ~50% utilisation. Obviously this made all the difference.
 
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Loksan3

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Nov 21, 2018
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Thanks for the replies and also the link to the Intel tool - very good!

This is happening in general. I've tried several different versions of HB - and a couple of kinds of input and output.
I first ran into it trying the newer H265 2160p60 Apple TV 4K HEVC output.
Then went to test Apple 1080p60 H264 which I've been using for years. Same.

It's happening in general. I started testing with larger ISO files (feature film type video TS) - but tested again with a simple 1GB QuickTime .mov file -> H264. Same thing... see screenshot. This should be a lightweight task IMO.

More disturbing however is the Lightroom exporting which I do regularly. A tiny run of outputting (30) 2000px JPG proofs shouldn't tax the system. It's going to go crazy when I hit it with hundreds of 8000px full resolution files! Fans never came on once before with these tasks.

I thought I was upgrading my 2015 iMac - but the blowing fans make it feel almost like a downgrade. :-(

I suppose the explanation could be - more horsepower - hotter processor = fans. It somehow just doesn't feel "right" though.

View attachment 844047
[doublepost=1561037376][/doublepost]Here's a downloadable link to a little 1GB .mov file that causes the fans to come one - test if you like....

https://drive.google.com/open?id=19CJPsHYEgdSOCB8rKDC5JKwzd7ZHWWDd
I don't have the new iMac 2019, but every review on YouTube say that this is the quietest iMac they have ever seen. Did you fix the problem? Have you noticed any spinning using any other aplications?
 

golfgirlgolf

macrumors member
Original poster
I don't have the new iMac 2019, but every review on YouTube say that this is the quietest iMac they have ever seen. Did you fix the problem? Have you noticed any spinning using any other aplications?
Generally it is quiet. It's just this "fans on" thing. According to replies it's not something to "fix" - it more of something to accept. So far I've only seen Lightroom also kick the fans on - I do run very large Photoshop files frequently so imagine when I start doing batch processing there, they will also come on.