hmm the examples in the installer are not really fast imho
I believe the sync speed is fixed - and isn't set to go as fast as possible. Its easy enough to change and re-compile.
but I have made some games with DBPro in the past, and found it to be extremely slow compared to most other engines. I haven't used it a while though, so they must have really improved.
DBPro is slow - GSDK isn't, because it's just the 3D engine, and none of the other stuff (code for while/for/repeat loops etc), that just isn't needed. When the GSDK first came out, I worked out that there was a approximately a 175% speed increase between DBPro code and C code with the GSDK...