Keatah

Set the resolution to 1600x1200 in the .cfg file. Build Engine at that res will cripple lesser machines.

Can I do that on the original DOS version from th 90's?

Yes. Just edit the duke3d.cfg file. It's just an ASCII file. Scroll down a little bit and you should see values like this:

;ScreenMode

; - Chained - 0

; - Vesa 2.0 - 1

; - Screen Buffered - 2

; - Tseng optimized - 3

; - Paradise optimized - 4

; - S3 optimized - 5

; - RedBlue Stereo - 7

; - Crystal Eyes - 6

;

;ScreenWidth passed to engine

;

;ScreenHeight passed to engine

;

;

ScreenMode = 1

ScreenWidth...