Ok, so I'm trying to get FSO running on my laptop with the following specs: i7-4710HQ, GeForce 970M, 16GB RAM, and 4K display. I've got everything installed and "running", but I'm struggling to get to the "running well" stage. This was all done with FSO 3.8, and the newest wxlauncher.
First, I try and fire it up in 3840x2160, with settings basically maxxed out, just to see what happens. I used Blue Planet's The Blade Itself for testing, as it is a fairly demanding mission, and I wanted somewhat of a "worst case" scenario. Running FSO in 4K, I could only get ~20 fps in this mission. Not surprising, the 970M was never really cut out for gaming in 4K. Now the weirdness starts.
So I switch FSO to 1920x1080 with max settings. An i7-4710HQ and 970M should be able to crush this game running at 1080p, and sure enough, the frame rate jumps to 80-90 fps, even in a demanding mission like The Blade Itself. There's just one problem - the game is only displaying in 1/4 of my screen. I figure display scaling (I had been running at 225% scaling) might be messing with things.
Thus, I drop scaling to 100%, restart my computer, and try again. This time, the game takes up the full screen, but I am back down to 20 fps. This is weird, so I take a screenshot, and sure enough, the game is still rendering in 1920x1080. Why on earth am I getting the same framerates as when it was running 3840x2160?
Next, I tried manually reducing my display resolution to 1920x1080 and leaving scaling at 100%. Same thing. Game takes up full screen, and is rendered at 1920x1080, but I'm only getting 20 fps.
Why do I get good framerates when the game is only displayed on 1/4 of the screen, but awful framerates when it is displayed in full screen, even though it is rendering at the same resolution? It doesn't make sense, but I'm out of ideas, and any help would be appreciated.
I also ran a debug build @ 1920x1080 with my display set to 3840x2160 & 100% scaling, and the results are attached.