Switchable Graphics is awful on Windows 10 2004 compared to 1607 (Dell XPS 9575, Vega M GL)

[phly95]

Running at a resolution of 3840x2160 on both Windows 10 2004 and 1607, there is a massive performance loss when using the dedicated graphics.

 

The problem is that this laptop while it has Vega M GL dedicated graphics, it can only output to a display by passing through the Intel HD 630. Before Windows 10 was updated to have "Graphics Settings" in the settings app, this was handled by AMD (with Switchable Graphics) and Nvidia (with Nvidia Optimus).

 

Neither is really ideal, as on a laptop, there is a total system power limit. This means the integrated graphics will draw power, and thus if the iGPU is running at 60%, that means that the dedicated graphics can only run at 30-40%. (it also impacts CPU performance)

 

Windows 10 1607 uses AMD's own implementation, and 2004 uses Microsoft's. Viewing a 4K60fps video on YouTube on 2004 results in a whopping 52% intel GPU usage, and 40% Vega GPU usage, but viewing the same video on 1607 only results in about 24% intel GPU usage.

 

Here's the worst part. Check out this footage from both versions of Windows when playing Muse Dash (had to choose something small for dual-boot). Keep in mind that Muse dash upscales to whatever your desktop resolution is, so 1080p in Muse Dash settings is still outputting to 4K. Both videos have the same settings in the attached screenshots.

https://youtu.be/z8BpL50L4J0 (New Windows 10 2004, latest drivers)

https://youtu.be/VwCfo0ABStA (Old Windows 10 1607, old Radeon drivers)

 

I don't even have an FPS counter, but you should be able to see the framerate difference from the video recording (be sure to set 1080p60 on Youtube). Windows 2004 feels like a stuttery 20-30 FPS, whereas Windows 1607 feels mostly like 60FPS.

 

Now of course, the effects are exaggerated with the screen resolution set to 4K, and setting the monitor to 1080p will be playable on both, but if the performance loss is so great at 4K, you are still leaving a lot of performance on the table when gaming at 1080p on the latest version of Windows 10, and that sucks. Increased power usage for worse performance. Why can't they just allow us to disable the Intel GPU altogether?

 

Images:

Windows 10 2004 https://linustechtips.com/uploads/monthly_2020_11/106737812_win10new-Copy.thumb.jpg.cb050638fc3ab952d8f7c45e555fcae6.jpg
Windows 10 1607 https://linustechtips.com/uploads/monthly_2020_11/2109946465_win10old-Copy.thumb.jpg.9bc743bf88c4c73af673398bd9747fd8.jpg
Resoluion and DPI scaling https://linustechtips.com/uploads/monthly_2020_11/1526320338_resolution-settings-Copy.thumb.jpg.121f5fcfe0075f3a0e040df9fa2c1f55.jpg
Muse Dash Game settings https://linustechtips.com/uploads/monthly_2020_11/1049224464_game-settings-Copy.thumb.jpg.a19e1ac6d12a97071f2e011d47a7e24d.jpg