On Fri, Dec 24, 2010 at 09:20:49AM +0100, Peter Stuge wrote: > alex au wrote: > > I was actually wondering how fast would the system run with 2 usb > > 3.0 sata ncq caddies of 1 tb hdd each? > > USB 3.0 is rather new technology and I expect that chipsets are still > buggy or plain slow. > > That said, the bottleneck is still mechanical disk vs. graphics card. > > I would go with eSATA instead of USB. Less layers. Look for a port > multiplier. Investigate if NCQ can traverse port multipliers and > report back to the list. Thanks! >
I have a port multiplier that supports NCQ with a single device. Since my motherboard does not offer support for FIS based switching, the total number of seeks on all devices on the port multiplier stays constant, because with command based switching each transaction must complete before another disk can be accessed (AFAIK). See also: https://ata.wiki.kernel.org/index.php/SATA_hardware_features I would try the SATA over USB setup, because sata port multipliers aren't cheap and a little extra overhead should be negligible when dealing with the few hundred hertz of hard disk access time. _______________________________________________ A51 mailing list A51@lists.reflextor.com http://lists.lists.reflextor.com/cgi-bin/mailman/listinfo/a51
