First post, by Keatah
I was setting up some old games such as Duke Nukem 3d and Ms SpaceSimulator, and Doom 1.666 and 1.9, and win3.1 for some other stuff. You know stuff like that. And I never quite got a good solid high framerate.
My hardware is a Centrino with Pentium-M 1.7GHz and Intel 855gm integrated graphics laptop from vintage 2004, running windows XP. Yes it is old, it is solid, reliable, and gets me good battery life and is relatively small.
So anyways, like in duke3d, the beginning of the first level, at the top, on the roof, I'd get between 4 and 20 fps! That is a simple scene! Erratically, most of the times averaging about 8 fps. Windowed or full-screen, made no difference. Switching back and forth between full and windowed seemed to "clear out" or load something into the video cache, because for a few moments I'd get 20+ fps. Then it would jerk its way back to 8 over 10 seconds..
After seemingly trying every conceivable option related to sound buffers and video drawing methods and resolutions and everything else.. I found a simple solution.
Since this is a lappy computer I found that by turning off the Windows XP speed throttling in the PowerCFG.exe I could make the cpu run steadily at max rate of 1.7GHz. Because, for some reason or other, DosBox doesn't like to put a full load on the cpu. And the cpu/winXP sensing that, likes to throttle itself down, thereby robbing DosBox of needed cycles. You can just set your lappy to always on and no speed throttling.
NOW, I get a good solid 25fps in duke3d, in 800x600 vesa 2.0 modes. All my other apps got rid of sound stuttering and everything dos-box related works a hella lot smoother!
So I made an extra power profile for use with dosbox, one that just turns the cpu on full burn.
So if you got some erratic framerates and are certain you have the cpu horsepower, check into the duty-cycle power-saving throttling.
