USB 3.0

paradisiac · 20 Jan 2011 at 16:07

i have several 2.5" hard drives laying around at home, so thinking i will stick them in enclosures and use them for backups and stuff.
i already have a couple in enclosures and find them a tad slow, is this down to being usb 2.0 or the enclosure/hdd? if its the speed of the port, would a usb 3.0 enclosure speed up the transfer rate?
also, i find that with the ones i have now (usb powered) anything over 250Gb (320GB sometimes works) seems to struggle to get enough power. again, would usb 3.0 improve this so i could get some of my 500GB drives in enclosures?

thanks in advance

DragonQ · 20 Jan 2011 at 16:19

USB 2.0 will limit real-world transfer speeds to about 40 MB/s. USB 3.0 can handle at least 400 MB/s so will remove that bottleneck. There still tends to be a little overhead though so it's usually a little slower than eSATA but not by much (< 5 MB/s).

paradisiac · 20 Jan 2011 at 16:22

so i would be better off getting esata enclosures? or do they not carry power?
oh but esata requires drivers for the enclosures doesnt it? so would need to carry the cd around with me too.

DragonQ · 20 Jan 2011 at 16:45

eSATA doesn't need drivers but it does need power I think, so I'd forget about that.

paradisiac · 20 Jan 2011 at 16:49

ok kool. so a decent usb 3.0 enclosure should make large file transfers a lot quciker (probs not the 10x like the figures would suggest) but do usb 3.0 sockets output more power, allowing larger disc support, or is that mainly down to my enclosures and not usb 2.0?

DragonQ · 20 Jan 2011 at 18:08

USB Website said:
50% more power is provided for unconfigured or suspended devices (150 mA up from 100 mA), and 80% more power is available for configured devices (900 mA up from 500 mA). This means that more power-hungry devices could be bus powered, and battery powered devices that previously charged using bus power could potentially charge more quickly.

Regarding transfer speed, you'll see a 2-3x improvement using USB 3.0 over 2.0. With USB 3.0, you're limited by the actual drive speed (as you would be if it was connected by IDE or SATA).

paradisiac · 20 Jan 2011 at 18:39

so could i plug a usb 2.0 enclosure into the usb 3.0 port to get the extra power or should a 500GB drive be able to run without power?