Edit DOSbox Options, there's a line "cycles=<value>" - the <value> is probably "auto" by default.
You could try 10000 or 20000 as the <value> first (about 386 speed), and see how it works.
Funny thing is that the DOSbox Options file itself says the numerical value needs to be "fixed <number>", but putting just <number> there works fine.
Here's how the [cpu] section looks like in my install for original Master of Orion:
Code:cpu] # core: CPU Core used in emulation. auto will switch to dynamic if available and appropriate. # Possible values: auto, dynamic, normal, simple. # cputype: CPU Type used in emulation. auto is the fastest choice. # Possible values: auto, 386, 386_slow, 486_slow, pentium_slow, 386_prefetch. # cycles: Amount of instructions DOSBox tries to emulate each millisecond. # Setting this value too high results in sound dropouts and lags. # Cycles can be set in 3 ways: # 'auto' tries to guess what a game needs. # It usually works, but can fail for certain games. # 'fixed #number' will set a fixed amount of cycles. This is what you usually need if 'auto' fails. # (Example: fixed 4000). # 'max' will allocate as much cycles as your computer is able to handle. # # Possible values: auto, fixed, max. # cycleup: Amount of cycles to decrease/increase with keycombo.(CTRL-F11/CTRL-F12) # cycledown: Setting it lower than 100 will be a percentage. core=auto cputype=auto cycles=21000 cycleup=1000 cycledown=1000
There's always the option of adding a GUI front end to DOSBOX. I use D-Fend - very convenient, and easy to jiggle settings for games.