Well, looks like there aren't any patches for the 4091. I tried burning a ROM for the 4091 with the early 4000T NCRscsi.device, with the predictable result of nothing happening. 
Looks like 4.5 MB/s is the best it's capable of, at least with my '060 card.
That's about what I get on my TekMagic, and was hoping for similar performance with the 4091. (Bought the 4091 after buying a Fastlane, which sadly arrived broken.) I'd stick with my DENEB, which works great... unless I attempt copying files between devices on the DENEB, then I get constant read errors.
Anyone have an old 4091 40.9 ROM they wouldn't mind parting with?
I have a few of these cards and I never got 10MB/s from them. I think I got about 6-7MB/s with a SCSI-2 7200RPM Cheetah HD. Make sure you turn on Synchro mode and that its properly terminated.
Do you have the 40.13 ROM update for this card? I have a few of them. Also have a 40.9 if you want one.
