Nvidia updated its support pages with an update on 4K UHD Netflix content playback in relation to the Windows 10 Fall Creators Update. Below the fold an overview of options, necessities. Something Nvidia notes, HEVC codec is no longer free. Microsoft requires you to purchase a license.

4K UHD Netflix content on NVIDIA GPUs To enable Netflix UHD playback, the following is required:

• NVIDIA Driver version 387.96 or newer driver.  No older GeForce driver will support this functionality at this time
• NVIDIA Pascal based GPU or newer, GeForce GTX 1050 or greater with minimum 3GB memory
• HDCP 2.2 capable monitor(s). Please see the additional section below if you are using multiple monitors and/or multiple GPUs.
• Microsoft Edge browser or Netflix app from the Windows Store
• Microsoft Windows 10 Fall Creators Update (10.0.16299 Build 16299 or newer): 
  https://support.microsoft.com/en-us/help/4028685/windows-10-get-the-fall-creators-update
• Approximately 25Mbps (or faster) internet connection.

Single or multi GPU multi monitor configuration

In case of a multi monitor configuration on a single GPU or multiple GPUs where GPUs are not linked together in SLI/LDA mode, 4K UHD streaming will happen only if all the active monitors are HDCP2.2 capable. If any of the active monitors is not HDCP2.2 capable, the quality will be downgraded to FHD. Below is a sample table for the case of 2 monitors:

SLI configuration

Currently, 4K UHD streaming is not supported for SLI/LDA configurations. However, if the GPUs are not linked together in SLI/LDA mode, 4K UHD streaming will work fine if all of the active monitors are HDCP2.2 capable.

Please note.  If you are using a fresh install of Windows 10 Fall Creators Update, you may need to go to the Windows store to purchase the HEVC codec to playback Netflix 4K/HDR content. Microsoft no longer provides this for free.

4K UHD Netflix content on NVIDIA GPUs (update) MS Pulls Free HEVC Support