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Borisz's Avatar
Join Date: Jul 2005
Location: dot hu
Posts: 356
the Dot Clock adjusts the speed of the main SH2 cpus at an approximate 1:7 ratio. So Dot Clock 2 means the Saturn is only running at half speed (14,3mhz) while at 4 it runs at full speed (28,6mhz).
Naturally setting it higher will drop the fps you are getting. It's set to 2 by default because that gives a good enough balance in compatibility and speed. Some games will experience slowdown or hangup though. One other game I know to be affected by this is Keio Flying Squadron 2 which has slowdown and will hang at one of the fmvs unless the Dotclock as at 3 or higher.
But the most obvious example would be the Saturn BIOS, in which the logo animation is not synched with the sound effect unless the Dotclock is set to 3 or higher.
The SH2 cache is not emulated by SSF so the Dot Clock should be set between 2-3 according to the readme. It "simulates" the main memory access wait time that the real system had that way. (in laymans terms: while dotclock 4 would be the most optimal choice, it may cause more bugs, so have it set between 2 and 3.)
ps: an athlon64 3000+ probably won't run most games at full speed without frameskip
my 3200+ (overclocked by 15%) can barely run the most simple games without frame dropping.
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