It's possible that a RTG graphics card in Zorro has to map chipRAM to be able to use as a means to get teh graphics info programs expect to put there. This said from someone who has no idea really.
If that were the case I'd assume all Z3 (probably Z2 as well) graphics cards would grab some chipRAM.
Best way to test is to remove it and boot the machine with just the 3.1 floppy. If you are still seeing the same chipRAM then either you have programs loading into that instead of Fast or something's wrong. Remember, a lot of Amiga cards seem to (at least to me) load some of what they need to operate even without loadig drivers from disk on startup. They have ROMs on board and the Amiga does autoconfigure them. So it's possible some software is loaded from the Retina even before you load any Picasso or Cybergraphics drviers from disk. though again I dont really know for sure.
My Retina ZIII went a little bad before I got an amiga that could run it reliably. I have a 4000/040 but its one with the buggy ZIII and 3.0 processor card so using any ZIII cards that run sustained data like a graphics board cause crashes when the 040 decides to grab things it shouldnt. Stpidly I left the Retina in the machine though and by the time I moved it to my new 4000/030 it started having artifacts appear on its screens. I maybe should try it in my 3000 to see if that is an issue with the 4000 when I have time.
