My review of Amazon’s Corsair 16GB USB 3.0 drive, http://www.amazon.com/Corsair-Flash-Voyager-Drive-CMFVY3S-16GB/dp/B005M21TBA
All those USB 2.0 flash drives are so slow that they are hardly limited by USB 2.0 itself, so, that’s why I got this USB 3.0 flash drive to use with my USB 2.0 systems.
It’s upsetting that the mainstream flash drives have literally zero information about their performance; this one has a minor exception in that they do mention the maximum read and write speeds over USB 3.0 that one may hope for.
I just unpacked this 16GB drive, and tried it out in my Atom netbook under OpenBSD 4.9. As far as the read speed is concerned, seems like one can hope for 20 MiB/s over USB 2.0, not bad, but I expected a bit higher.
umass0 at uhub0 port 1 configuration 1 interface 0 “Corsair Voyager 3.0” rev 2.10/a.00 addr 4
umass0: using SCSI over Bulk-Only
scsibus1 at umass0: 2 targets, initiator 0
sd0 at scsibus1 targ 1 lun 0:
sd0: 15320MB, 512 bytes/sec, 31375360 sec total
hype: {2520} dd if=/dev/rsd0c of=/dev/null bs=16k count=8k
8192+0 records in
8192+0 records out
134217728 bytes transferred in 10.240 secs (13106257 bytes/sec)
hype: {2521} dd if=/dev/rsd0c of=/dev/null bs=32k count=4k
4096+0 records in
4096+0 records out
134217728 bytes transferred in 8.018 secs (16737999 bytes/sec)
hype: {2522} dd if=/dev/rsd0c of=/dev/null bs=64k count=2k
2048+0 records in
2048+0 records out
134217728 bytes transferred in 6.591 secs (20360708 bytes/sec)
hype: {2523} dd if=/dev/rsd0c of=/dev/null bs=128k count=1k
1024+0 records in
1024+0 records out
134217728 bytes transferred in 6.593 secs (20357611 bytes/sec)
hype: {2524}
However, accessing it through the non-raw volume is really slow, looks like a CPU bottleneck? Will have to take a closer look sometime.
hype: {2526} dd if=/dev/sd0c of=/dev/null bs=128k count=1k
1024+0 records in
1024+0 records out
134217728 bytes transferred in 49.323 secs (2721156 bytes/sec)
0.020u 9.630s 0:49.36 19.5% 0+0k 65538+1io 0pf+0w
