The maximum resolution from your Mobo VGA Port is 1920x1200@ 60Hz, 24bpp
The maximum resolution from your Mobo DVI Port is: 2560x1600@60Hz, 24bpp/ 1920x1200@60Hz, 24bpp
Seems like all DVI-HDMI only outputs Full HD 1080P resolutions.
According to this game site the Maximum Resolution for the HD8370D is 2560x1600:
he only adapter outputting DVI 2k are generally DP-DVI adapters.
So it seems like you are restricted to 2560x1600 output to your monitor if you are able to find a DVI-D - HDMI Adapter that will output that resolution.