Original Apple TV 4K sluggish with Dolby Vision

[slyronit]

I have an original Apple TV 4K. Lately the UI is visibly sluggish when scrolling or navigating, especially when typing something using the on-screen keyboard.

Videos play fine.
If I change from Dolby Vision to HDR, there’s no sluggishness.

I know the new 4K has a faster CPU, but that alone is not something that would make me upgrade.

Is this a common thing?

 

[-Gonzo-]

Personally I feel no need to have it set to Dolby Vision or HDR all the time, I just leave mine set to 4KSDR then let Match Dynamic Range take care of when Dolby Vision or HDR is required.

 

[slyronit]

That's interesting, and would theoretically solve my problems. But with this, every timer you start or stop a video, the screen would flicker as the TV switches to the new mode yes?

 

[slyronit]

Yep, looks like there's flickering every time the video mode changes. This is OK for TV shows and movies, but swiping through iClown photos and videos becomes unbearable. It clips off the first second or 2 of every video.

Guess I will have to live with the sluggishness.

 

[slyronit]

On a whim, I opened it up, expecting the heatsink/fan to be clogged with dirt. However, to my surprise, it was pristine inside. I connected it and played 4K HDR videos while the fan was exposed and in half an hour, it didn't turn on once. Also, looking at how clean it is inside, looks like the fan has never worked.

 

[w5jck]

I use the following settings on my ATV 4K 2017:

• Format: 4K HDR*
• Chroma: 4:2:2
• Match Content: Range & Frame Rate

*Setting format to 4K SDR also works well, but you won’t see the 4K HDR aerial screensavers.

As far iCloud photos and videos, the tvOS 15 Photos app is pretty much garbage. Photos that are saved in Display P3 and are 16-bit show banding and color issues because apparently Photos on ATV can only use 8-bit color. Photos seems to use SDR rather than HDR. The same photos look great on Mac, iPad, iPhone, etc., or when used in the screensaver app on the ATV. But I haven't noticed any video issues other than the colors being downgraded to 8-bit.

It does sound like your ATV 4K 2017 might have an issue. Mine doesn't get sluggish unless there is an internet issue or a poorly written 3rd party app like Philo.

 

[-Gonzo-]

The sluggishness is cause by some sort of interference of the Bluetooth signal.
Using the iOS ATV remote over Wi-Fi or using the learn remote function on an existing IR remote then all navigation is smooth.

 

[slyronit]

I can confirm that my ATV fan is broken, perhaps has been forever. I ran a benchmark app on it and the numbers are far below what is standard for this device. Even during peak benchmark, the fan doesn’t turn on and the stuttering is more evident immediately during and after the benchmark, which is when the device is also at the hottest.