Tested using "Raw block speed" test in LIDO 7 under MacOS: [SCSI2SD v5] READ: 891 KB/s WRITE: 728 KB/s [ACARD ARS-2000SUP] READ: 1621 KB/s WRITE: 1277 KB/s More info: The ACARD device contains a Samsung 850 Pro 128G SSD. The SCSI2SD contains a Samsung Pro+ 64GB micro SD and is running firmware v4.6, IIRC. Both are were attached to a Quadra 700 Macintosh running System 8.1 with 68 megs of RAM (4 onboard + 64MB in 16MB SIMMS, the max on the Quadra 700). I had them hooked up at the same time so I could use one to partition the other. The hard disk "driver" was the one provided by LIDO, but I also tried LaCie SilverLining 5's driver as well, but the performace was slightly worse. I tested in LIDO using it's raw speed test feature. It's probably only a rough measure of sequential speed. I just tested three times and averaged the results, but it was within just a few KB/s each time. Once I'm done I'll hook both of these up to a FreeBSD box, dd off full backups, then start over again and try with ZFS under FreeBSD via a PCI SCSI controller. Then again under IRIX if I still have the energy. I'll give some results from 'fio' or 'iozone' under FreeBSD. Those will be a lot more detailed and break down sequential versus random results and show the results of various other permutations. I'd also like to test the SCSI2SD v6, but I can't get my hands on one, yet. The only place that talks about the v6 is the codesrc wiki and the American ebay retailer seems to only have the v5.0. I'll wait, I guess. -Swift