Hi, all. I just completed my first build from scratch and am running Deepin. I don't game, and I thus opted for an integrated graphics card (Intel i5 9600K) rather than having a separate GPU. I am disappointed in the 4k video quality. I have tried YouTube test videos as well as a downloaded a 30s test clip from Captain Phillips, which was also choppy, which makes me think my internet speed is not the primary culprit. I use a Dell U2718Q monitor that I used as a second monitor with my previous Apple laptop and did not notice significant 4k lag. I also know its specs are sufficient. The monitor is connected to my MSI MPG Z390 Edge AC motherboard via DisplayPort to DisplayPort cable. My OS resolution is set at 3840x2160. I thought that turning down the "Display Scaling" (from 2.0->1.0) helped at one point, but I was not so sure on subsequent viewings.

My searches thus far have indicated to me that the i5 9600k (and its integrated graphics) should be able to handle 4K video. Is there some setting I need to be tweaking with the Intel graphics chip? Deepin has something called the "Graphics Driver Manager" which purports to accelerate the Intel graphics, but I noticed no difference when using it. Thank you in advance.

What source do you play the 4K video from and what software do you use? I suppose you switched from Apple to Linux? So did I and I am happy with it.

However I have a AMD Ryzen 7 (1st gen) that also has choppy 4K video, and my system sports a NVIDIA GTX 1050 TI so that does not seem to be the bottleneck. I am as curious as you are about a possible solution..

Should be sufficient imo.
I don't think the monitor is relevant, but resolution might be, and how it's connected.
The video file is relevant, the desktop environment, drivers etc.
Can you post a link to a video that is choppy?
Also, can you define choppiness? Is your system under very high load?

Also show us:

Looking up Intel i5-9600K functionally gets the same information, device ID (8086:)3E98 and exactly or some variation on UHD Graphics 630 (Desktop 9 Series).

Video playback of any high quality kind depends on the adequacy of the source of the video. If it's coming from an internet connection that is sharing bandwidth with other users, including those next door and up the street, 4k video playback can suffer through no fault of the GPU or the PC hosting it.

The OP downloaded a 30s clip to their drive which still had problems.

Captain Phillips wasn't a link, so no idea what quality it might have, or ability to try it. What is the quality playing a Bluray or a HD stream from a major TV network?