How to speed up DOSBox (by robertmo and mirekluza)

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How to speed up DOSBox (by robertmo and mirekluza)

Postby mirekluza » 2004-5-25 @ 05:10

1. Close every program but DOSBox

2. Turn off all the scalers:

Edit dosbox.conf and set:

[sdl]
fulldouble=false
fullfixed=false
fullresolution=0x0
output=surface

[render]
aspect=false
scaler=none

3. Run DOSBox in a fullscreen mode:

hit Alt+Enter after running DOSBox

(if you have black stripes at the top and the bottom of the screen go to your display driver settings and change refresh rate for these two resolutions: 320x200 and 640x400. ("60Hz" and "default" is bad so set something else: "70Hz" or "75Hz" or higher). If you have a LCD (thin) monitor, connect a CRT (normal/big) monitor for a while, change refresh settings, make sure they work correctly, and connect your LCD monitor back.)

4. Set mpu401/GeneralMIDI instead of Sound Blaster for music in your game's setup if it is possible.

5. Set GUS/Gravis instead of Sound Blaster for sound/digital audio in your game's setup if it is possible.

5. If you really want to use DOSBox in a windowed mode (which is slower than fullscreen) you should set your desktop to 16 bit color.

6. If you want you can reduce audio quality:

Edit dosbox.conf and set:

rate=11025
oplrate=11025
rate=11025
pcrate=11025
tandyrate=11025

7. You can use unstable dynamic core:

Edit dosbox.conf and set:

core=dynamic

It may speed up the game but it may also make the game not runable or to crush often. So if your game crushes/doesn't work dont use it. Even if your game seems to work fine save often ;)

8. Setting cycles/frameskip:

You should go here now:
viewtopic.php?t=2502
-> STEP 3 - Performance

Could this be added to "DOSBox Guides" forum?
Done :-)
Last edited by mirekluza on 2005-1-16 @ 16:58, edited 4 times in total.
mirekluza
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Re: How to speed up DOSBox (by robertmo)

Postby mirekluza » 2004-5-25 @ 19:12

I would add the following to the above mentioned:

Try different output methods (setting "output" in DOSBOX.CONF). The most basic is "surface". For some people "overlay" works quicker. The third possibility is "opengl" or "openglnb" (one of them uses filtering - picture is less pixelated, but also less sharp).
These methods have also different influence on the speed of DOSBOX in fullscreen. Fullscreen using "surface" is quicker than window, but fullscreen using "opengl/openglnb" is slower than window.
"opengl/openglnb" is be also slower on non-NVidia graphic cards (DOSBOX uses some non-standard extension of OpenGL on NVidia cards to transfer textures quicker).

Mirek
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Problem with non-USB joysticks

Postby mirekluza » 2004-6-14 @ 06:03

Do not use non-USB joysticks in DOSBOX. This was several times reported as causing severe slowdown and sound skipping on even the most powerfull PCs. USB joysticks should be fine.
So if sound is skipping in all your games or if DOSBOX always uses 90% of resources on your computer, then throw away your old joystick.

Mirek
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Re: How to speed up DOSBox (by robertmo and mirekluza)

Postby robertmo » 2009-7-12 @ 10:02

Don't force on vertical sync in your display drivers as it may slow down your opengl/openglnb outputs in some resolutions that use higher refresh rates than your monitor.

Update for new versions of dosbox (since version 0.65):

[sdl]
fulldouble=false
fullresolution=original
windowresolution=original
output=surface
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