My bad :-) Can you remember which kinds of Simm work, Cyberus?
I think this is a case of the 2Mb on the MB running out, then the slower being used pretty quickly - it certainly explains why Workbench seems fast, but games slow!
If you can find a set of 16Mb for the MB then it'll only slow when you run out of fast memory (I think that made sense ...).
When I was talking about disabling the SCSI memory I was thinking to work out how much memory was needed, but you know already, so no worries.
TJ is in the enviable position of having memory to cobble dogs with, I've got 16Mb in my A3000 and now 8 in my A1200 :-)