So would a Picasso IV (Z3) be say, twice as fast as a Picasso II (Z2) when used in an A4k? Also, would a Picasso II benefit from running on a Zorro 3 bus at all?
A Z3 P4 would be more than 2x the speed of a P2 but it has more to do with the GPU and gfx memory speed than the gfx bus speed which is faster too. Gfx speed usually has more to do with scrolling, line drawing and block filling (select SIMPLE refresh windows where possible) which benefits more from a fast GPU than bitmap and text updating which benefits more from a fast gfx bus. The Voodoo 3+ with a Mediator blows away the P4 at most operations despite the P4 having significantly faster gfx bus speeds. The Mediator is closer to Z2 bus speeds than Z3 bus speeds even on big box Amigas. Most Z3 gfx cards are not near the potential of Z3 either. The CV64 (not 3D) probably came the closest and is faster than P4 with less colors and lower resolutions. Some cards like the GVP Spectrum are so slow that they offer little if any benefit despite claiming a Z3 mode. Z3 is pretty slow even compared to PCI but the biggest bottleneck is usually going to be the 68k CPU.
The new fpga Amiga's should be worth a look as compared to a 1200+Mediator. The FPGA Arcade will have a 68060 add on board available very soon and 2D only 1 monitor RTG support with Ethernet available any time. It will probably be competitive with upgrading a stock 1200 and probably easier in a lot of ways. The Natami should be available some time this year with more expansion including full speed PCI slots and more speed but with a higher price.
