This is a great discussion thread as I've found many people posting similar problems with 4K and HDR support in other forums. I know your topic is referencing 4K to external monitors, however, in this reply you stated that the SB2's internal display plays Netflix at 1440p and it supports windows 10 HDR. However, I'm not able to get my to play either content. I've verified the codecs, verified HDR is enabled, SB2 windows updates are current and I've downloaded the latest drivers from Nvidia. The tech at the Microsoft store and the tech on the phone was unable to get it going even after replacing my SB2 with a brand new one (was less than 14 days old). Any help is appreciated. Thank you!
I'll go ahead and copy here what I posted on Reddit. First, is yours a 15" or a 13.5"? I've only tested all of this on the 15" model and can't verify what works with the other model:
Okay, so, one of my pet peeves with the Surface Book 2 is the lack of HDCP 2.2 support for external wired displays (i.e., no Netflix 4K support). So, I was pretty excited to see that Microsoft has improved premium content support on the
internal display -- it will now scale up higher than 1080p and it supports the Windows 10 faux-HDR support.
But, it's actually more complicated than that. There's apparently a choice between 1440p
and HDR support, and 2160p
without HDR support. And yes, I know: the SB2 15" display isn't actually 4K, being just 3,240 x 2,160 and not 3,840 x 2,160.
Here's the trick: Go to Settings > Apps > Video playback. If you're on A/C or battery, then toggle off "Stream HDR video." If you're on battery, then you can also keep that toggled on and then under Battery Options check "Don't increase display brightness when watching HDR video on battery."
If you turn off the HDR streaming support, then you'll find that 4K Netflix content will stream at the full 4K bitrate (obviously there's some kind of scaling being done). You can check this by hitting Ctrl-Alt-Shift-D while the video is playing. Note that the Netflix app (or maybe the Edge player, but I haven't tried it) will say that the video supports HD and not 4K UHD, which is accurate but not precise -- the display really doesn't support native 4K UHD but it does support higher than just HD.
If you turn/keep HDR streaming support on, then you'll find that 4K/HDR Netflix content is limited to 1440p, in both bitrate and in what Ctrl-Alt-Shift-D defines as the current resolution. And, the Netflix app will indicate that HDR is supported (which is what it will say when content is both 4K UHD and HDR).
tl;dr: The SB2 15" (maybe also the 13.5") supports higher than 1080p Netflix video and faux-HDR, but you gotta play with the settings. And sorry for the title typo (the "wh" shouldn't be there).