Not to mention that the 020 has cache - not a lot, but enough that it's not completely bound to external memory the way the 68000 is.
No question that a stock 1200 is a good deal slower than one with fast RAM, but let's not get crazy here.
I agree. The 68020 has a 256 byte instruction cache but no data cache. It also has 16 general purpose registers. The chipset doesn't need all the bus cycles unless running high resolutions with lot of sprites and lots of sound/music. With efficient code, the line drawing part isn't a problem. The filling or texturing is more difficult. I would expect the 3D computation and collision detection to be the most difficult. These would still be table lookups on the 68020 and that is where fast memory and a data cache would be beneficial. Many 3D environments for low end machines are pseudo 3D that still look good. It may be possible to pre-calculate some 3D data if there are limitations on movement/path in the 3D environment. Some demos use tricks like this.
