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vanc

macrumors 6502
Original poster
Nov 21, 2007
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For Youtube 8K videos encoded with AV1, on my MBP 16 with M1 Pro, the playback is very smooth, but CPU usage is very high. Whole system power usage reached about 35w to 40w. This is an example:

The `Stats for nerd` overlay on the video. Only 4 dropped frames for me.

1700007996841.png


The 8K playback is only available on Google Chrome and Firefox. On Safari, the best option is 4K. I'm on Ventura 13.6.2 with Safari 17.1.

Google Chrome gives hardware acceleration information in the chrome://gpu page. For M1 Pro, here is what I got.

1700007743199.png


If you have a M3 MBP, do you mind to try the video out and check your system CPU usage? I'm curious how effective the AV1 hardware acceleration is.
 

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For Youtube 8K videos encoded with AV1, on my MBP 16 with M1 Pro, the playback is very smooth, but CPU usage is very high. Whole system power usage reached about 35w to 40w. This is an example:

The `Stats for nerd` overlay on the video. Only 4 dropped frames for me.

View attachment 2312396

The 8K playback is only available on Google Chrome and Firefox. On Safari, the best option is 4K. I'm on Ventura 13.6.2 with Safari 17.1.

Google Chrome gives hardware acceleration information in the chrome://gpu page. For M1 Pro, here is what I got.

View attachment 2312394

If you have a M3 MBP, do you mind to try the video out and check your system CPU usage? I'm curious how effective the AV1 hardware acceleration is.
Just curious, why are you staying on Ventura?
 
Just curious, why are you staying on Ventura?
Just for the peace of mind. I'm using the MBP 16 for work. And I don't have problems with Ventura for my current work flow.

I do have another MBA 15 for casual use and I did upgrade to Sonoma when 14.0 GA was released.
 
8k60 YouTube AV1 playback works on Safari in Sonoma. I tried the same video on my M3 Max binned 16”, Safari uses only 40% CPU while Chrome uses like 700%

I did this test a few days ago and didn’t take screenshots, I can do that again but I am not with the MBP now (it is at work).
 
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What does 700% mean exactly? Swap file 6X the total RAM? Was that a typo , did you mean 100?
Depending on where you look, the value you see in Activity Monitor (or other tools) is not the percentage of the total CPU usage, but per core/thread (the Unix way).
If the methodology from the Intel days is the same for AS, I'd explain it this way:
Said binned M3 Max has 14 CPU cores in total (10x performance and 4x efficiency).
So 40% means one core is utilized to 40% resulting in (40% / 14 cores) = 3% total CPU usage.
700% means seven cores are utilized to their fullest resulting in (700% / 14 cores) = 50% total CPU usage.

EDIT: Depending on how an app uses the CPU or macOS manages it, 700% can also mean, all 14 cores are each utilized to 50%. But the product is mathematically equal.
 
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Screenshot 2023-11-16 at 17.54.35.pngScreenshot 2023-11-16 at 17.58.05.png

Okay I ran that New York video and these are the results. Clearly Safari is using AV1 decoder while Chrome does not. There is almost a 10x difference in CPU % usage which is ridiculous. I myself still prefer using Chrome on macOS for anything google related, especially considering the Adblocker situation and the absence of ublock origin on Safari as an extension. For now I may have to use Safari but once Chrome gets version 120 I will go back.

re: larger than 100% usage meaning
yes, in unix terms, one core is considered 100% where your multi-thread tasks can then be using larger than 100%, that's how iStat menus default is setup and it is also an easier way to compare usage between machines with very different core count configs. The M3 Max with 14 CPU cores is indeed maxing at 1400% accordingly, so playing back that video without AV1 hardware transcode takes almost half the CPU cycles for software brute decode. But I have to say even then it is really impressive, there is no frame drop, and this is just a laptop.
 
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Tested this.

on 16" M1 Pro it hit around 80% CPU
on 14" M3 Max 14 cpu 30 gpu it hit around 43% CPU

Both on Chrome and 8k full screen
 
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Tested this.

on 16" M1 Pro it hit around 80% CPU
on 14" M3 Max 14 cpu 30 gpu it hit around 43% CPU

Both on Chrome and 8k full screen
I doubt Chrome only used 80% CPU on M1 Pro. For me, it's about 650%.

Make sure select the 8K quality. You can confirm with the "Stats for nerd" overlay.
 
Chrome doesn't support the M3 AV1 hardware decoder yet; it will be rolled out with Chrome version 120.


So if you try 8K AV1 on an M3 MBP now, you'll likely see similar power usage. After M120 and AV1 HW decoding is turned on, you should see much lower power usage.
I don’t think Chrome 120 has support yet nor will Chrome 121 which releases today - the project seems to be abandoned according to the link?
 
I don’t think Chrome 120 has support yet nor will Chrome 121 which releases today - the project seems to be abandoned according to the link?
I notice this as well, using Chrome on macOS still consumes upwards to 700% CPU cores on an Apple Silicon Mac, when playing demanding AV1 videos. Google's recent "battle" against adblockers also is spicing things up a bit, with Chrome I can no longer reliably get the AV1 stream to load, it gets the VP9 instead which caps at lower res / no HDR etc.
 
I don’t think Chrome 120 has support yet nor will Chrome 121 which releases today - the project seems to be abandoned according to the link?
I am not a Chrome/Chromium expert, but it sounds like the change was merged into M120 and M121, but is disabled by default. You can enabled it using this flag

chrome://flags#video-toolbox-av1-decoding

(that's in comment 2 in the bug)

They also say something about M120 being a different code path. So if you have an M3 and Chrome 121 or later, you can change that flag, restart Chrome, and see what happens.
 
AV1 hardware decoding option is indeed available in Chrome 120. It's just off by default.

1705692431203.png
 

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Google's recent "battle" against adblockers also is spicing things up a bit, with Chrome I can no longer reliably get the AV1 stream to load, it gets the VP9 instead which caps at lower res / no HDR etc.
Perhaps it somehow requires premium subscription?

I just tried a couple of 8K videos, and they played just fine. Chrome still used a lot of CPU, around 700% (10 core M1 Pro). But no frame drop. With 4K video, CPU usage was super low due to hardware acceleration.
 
Perhaps it somehow requires premium subscription?

I just tried a couple of 8K videos, and they played just fine. Chrome still used a lot of CPU, around 700% (10 core M1 Pro). But no frame drop. With 4K video, CPU usage was super low due to hardware acceleration.
I think YouTube would decrease the required bandwidth of available options depending on multiple factors, like if it is peak hours, and whether or not it detects adblockers are used as well. And today I got no issues playing back any 8k stream. It is hard to grasp.
 
I’ve hard to force this flag off today on a new m3 max.
Set as default or enabled and all av1 video in YouTube is simply unwatchable, even though the stats says 0 frames drops it watches like 10/15fps content .

Absolutely fine when set to disable, and also fine in safari
 
I’ve hard to force this flag off today on a new m3 max.
Set as default or enabled and all av1 video in YouTube is simply unwatchable, even though the stats says 0 frames drops it watches like 10/15fps content .

Absolutely fine when set to disable, and also fine in safari
Can report similar issues on my M3 Max. It seems the frame drops don't always happen, but when it does it is even present on a 4k24p AV1 video. My Chrome install is on the latest 121.0.6167.184 build.

I don't remember seeing this in the previous builds, so probably a newly introduced bug.
 
Can report similar issues on my M3 Max. It seems the frame drops don't always happen, but when it does it is even present on a 4k24p AV1 video. My Chrome install is on the latest 121.0.6167.184 build.

I don't remember seeing this in the previous builds, so probably a newly introduced bug.
I too noticed the "not all the time" issue. On investigation, the videos that were ok were using VP9, rather than AV1, which help me narrow down the cause. Had no iissue on my previous M2 Max, so one suggests it's related to these new decoders.

Same build here:
Version 121.0.6167.184 (Official Build) (arm64)
 
chrome 122.0.6261.69 (Official Build), (arm64)
M3 pro, same issue - av1 on youtube watches like 15fps. Fine in safari. Also fine on chrome with disabled AV1 in chrome://flags
 
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Sorry to bump this thread, but it's actually important to me to be able to watch 8K YouTube with AV1. Anyone with M3 MBA or M3 MBP try the above tests recently with Chrome?
 
Sorry to bump this thread, but it's actually important to me to be able to watch 8K YouTube with AV1. Anyone with M3 MBA or M3 MBP try the above tests recently with Chrome?
It seems the choppiness of enabling AV1 is gone since 122.0.6261.112. At least I haven't stumbled upon a video that would lag since.
 
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