Interesting. I wasn't expecting that, I've heard a few times that mixing 16 and 32 bit memory slows the accelerator (not necessarily the transfer performance of the SCSI interface).
Your GE-Force has a SCSI interface included, right? So your 2000 doesn't have an A2091?
I asked because I have an A2500 with Commodore's 030 accelerator, 32-bit fast ram, A2091, and NO 16-bit Fast Ram anywhere (the Chip Ram is 16-bit, of course). It makes sense to me that some ram on the A2091 would improve its transfer rate, buffering, etc.
Correct, I'm using the SCSI interface on my GeForce card. As Ralph Babel noted on his own website, the transfer rates of SCSI on the accelerators is slower than that on the GVP HC8+ series of cards, dunno why but it is what it is. I've done everything in the book to speed it up, PFS file system, loads of buffers, latest 4.15 ROM (still looking for a Guru ROM), but for whatever reason adding that 16-bit fast really seems to have helped.
Your logic is sound, add memory directly to the controller to improve its buffering... from what I recall in my testing with a HC, I was getting somewhere close to 3MB/sec when loaded with memory, and only about 800KB/sec with zero memory. Using the GeForce SCSI controller I get about 1.7MB/sec, maxed out. Still quite usuable once you factor in all the patches.

I'm running TLSFmem and most Amiga programs should use the 32-bit memory first, but I think some programs and bits of code are still "hard-coded" to use 16-bit, and thus adding that fast mem helps (otherwise data passes through the chip mem address range to get to the 32-bit fast).
This is all just from memory and it's 3am right now, so don't quote me 100%, lol. :drink: