Yes, however I managed to buy up only four units (back in 2011 when they were a 1/10 of the current price). Good luck now...
Also SGI Parallel SCSI stopped at Ultra 320, I think, or Ultra 160. I've not seen any device with Ultra 640.
ACARD ARS-2160H :
http://www.acard.com/index.files/Page675.htm
There was a 68-pin version, but I never found it, only 80-pin SCA versions. For some reason these have been out of production for like 7-8 years? I guess. because they are no longer sold - the prices on eBay are now $1,000+ for a unit.
For some reason, I updated the firmware on mine when I got them in 2011 to a 2010 firmware just fine, however I cannot update them to the last firmware now (using XP and all), the firmware updater just fails. Current version is 1.19, I'm stuck at like 1.14? But since the firmware date is PAST the date for SGI MIPS production, I don't think it really matters.
As for how fast, well I've not tried it with an SSD because I would have needed an SLC SSD (still overly expensive in 2011, now I can get them cheap on eBay), as TRIM commands won't be issued, so you'll slow down once every cell is written. At least on an SLC, your "overwrite" operation (read, blank, write) would be the fastest (but still slow). However you do keep up with the native bus speed. I've tried them in an O2 and a Tezro. Obviously it's a waste in an O2, and can keep up in a Tezro. Even a normal SSD SATA 2.5" drive in this adapter was moving at the SATA drive's fastest mechanical speed ~120MiB back in those times. Unsure how much faster it would actually go given flash.
I'd say you can try cheaper CF tricks for like narrow and Ultra-Wide SCSI buses, but you'd need the big-boy stuff for LVD speeds. These are the best that was ever put out (to my knowledge). I do know more M-Flash based SCSI FLASH drives have been showing on eBay for 50-pin systems...but still command $300+ for like 1.2GB. I don't own any of those.
The basic problem is, once Windows DROPPED ALL PARALLEL SCSI support at Windows 8 and higher, manufacturers retired all the SCSI adapters and everything- so that was what 2012? Well now we're really feeling it. It's nice that the community is trying to make new adapters, but for some reason there isn't enough call for REALLY fast SCSI to flash stuff to be produced at volume.
Best of luck, in truth a modern, later model SCA SCSI IBM or Fujitsu drive can be very nice and most of my systems use them. I reserve the SCSI bridges for only the fastest + highest valued systems. It's a waste on much of anything else...unless you got a bunch at a good price.
Also, I've been very fearful of NAND data retention and I only boot the systems ever year or so and only for a short while. And older SLC SSD won't have block moving for Cell health, and MAY suffer corruption after 10 years of non-powered data refresh. Modern flash drives MOVE data around as they have power to refresh cells so the charge doesn't degrade. Old SSD drives don't do this. So it's entirely possible that you load your vintage machine with a flash storage, then come back to it a decade later and it's corrupt. As long as you keep a backup image to restore, it's a non-issue. But if you manually loaded and don't have the knowledge or original software discs...you could lose it all. Flash was made to be USED, not stored, long term.
So far I've not had any SCSI HDD fail in my collection (store in a heated home). However garage and barns will destroy old drives. For now I've stocked up on nice, cheap SCSI drives when I can. If I was experimenting, I'd use flash, but not a for long term storage right now.