Can't get Windows 10 to output native 1366x768 resolution to HDTV, instead it software scales 1080p down to the lower res which looks horrible -- Windows 7 does not have this problem (i.e. Win display setting 1920x1080 -> TV 1080p, Win display setting 1366x768 -> TV native 1366)

I have a Samsung HDTV which supports both 1080p and a native 1366x768 input mode. When browsing from the couch I prefer 1366x768 @125% DPI, it's easier to read and just plain looks better than 1080p @150% DPI. With Win7 the TV will actually switch its input mode to the native 1366x768 automatically when I change the display resolution in Windows. Not so with Win10, regardless of the display res set in Win10 the GPU always outputs a 1080p signal and the lower resolutions are software scaled down (looks horrible).

So far I have been unable to find a fix for this in Win10. I did come across an article which explained how Win10 changed DPI scaling to accommodate the fact that phones and tablets can turn sideways. The article also pointed to a REG hack to put the scaling back to the way Win8 does it with a program called Windows10_DPI_FIX, unfortunately that didn't solve the problem.

I have two PC's that I've tried, one w/Nvidia GPU and the other w/AMD:
R9 270X GPU
Asus P8B75-M/CSM MB


I'm reasonably certain it's a Win10 driver issue. When I upgraded PC2 from Win7 to Win10 the TV was still using its native 1366x768 mode before I manually updated to the latest Nvidia Win10 driver. I've since performed clean Win10 installs on both PC's and the TV will not change input mode like it does w/Win7 -- seems like Win10 always wants to output the display's highest resolution (HDTV 1080p in this case) and software scale the lower 1366x768 res.

Any ideas on how/where to find a fix for this. If I can't fix this I'm going to have to roll back to Win7