USB 3.0 works under Linux

I decided that I needed a real backup solution, even though I have a RAID 5 for file storage in my workstation; maintaining a backup of a 2TB array is a pain in the ass if all you have is blank DVDs.

So, I purchased a Vantec NexStar 3 SuperSpeed (NST-380S3) enclosure, a Samsung EcoGreen F3EG 2TB 5400rpm (HD203WI) drive, and a USB 3 PCI-E controller.

It seems the only shipping USB host controllers the moment all use NEC’s USB 3.0 chip, and almost all the PCI-E boards look alike. They all seem to run in the $25-45 range. The great part is Linux supports NEC’s controller as of 2.6.31. The controller worked with no configuration soon as I put the card in.

I chose that specific Samsung drive because it seems to be the only sane 5400 rpm 2TB drive out there. The only other choices were Seagate’s new 5900 rpm drives (which, according to independent reviews on Newegg and enthusiast forums have an unacceptably high failure rate, very unusual of Seagate), and Western Digital’s Caviar Greens (which are 5400 rpm, but suffer from obsessive head parking which is apparently leading to premature drive failure).

Several reviews peg the HD203WI at an average of 90mb/sec writes for sequential writing, or about 2-3x the speed of USB 2.0.

mkfs.ext4 took 7:44 minutes to create the file system (while iotop confirmed it was doing in excess of 100mb/sec writes for much of the process), and hdparm -t /dev/sdx also indicates the drive in this enclosure can push 100mb/sec.

After writing to the drive for an hour straight, the enclosure is warm but not hot, and after removing the drive from the enclosure, the drive itself is warm; this is compared to the Seagate 7200.12s in my RAID 5 array which could burn you at this point.

Many drives fail in enclosures because they overheat; I don’t think this will happen due to Vantec’s thick aluminum design in the NexStar series enclosures, and the fact that the HW203WI has low power usage.

After formatting with ext4, the file system uses 29GB out of 1.82TB total. Its kind of funny when I’ve owned drives smaller than the space consumed by an empty file system.

I’m rather happy with my purchases overall.

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Published August 22nd, 2010


5 Responses

Just curious: Why would you choose USB 3 over eSATA at this juncture?
eSATA devices are cheaper and more available still.

Because many eSATA enclosures, instead of merely passing the SATA data pins through to the host, install some sort of bridge chip instead. These bridge chips often do not support SATA 2.0 devices at 3gbit (even though eSATA on the outside runs at 3 gbit), some won’t even connect to SATA 2.0 devices unless the jumper on the drive is set to “force SATA 1.0”, and some do not correctly deal with drives above 750gb.

And, unfortunately, many manufacturers also do not disclose what bridge chip they use, nor what specification and drive sizes they support. Some manufacturers also update their product to eliminate these problems, but do not create a new model name, but instead keep shipping using the old name, and stores don’t disclose which version you’re buying.

So, screw it. I was going to go with eSATA, but at least with USB 3, all the USB 3< ->SATA controllers support at least SATA 2.0 and 2TB+ drives.

It’s great to know USB 3.0 works nicely. Regarding the 2TB disk, you could reduce the “reserved space” on the filesystem (you can gain a couple of GB’s) by using tune2fs. Check out here:

I suggest changing it from 5% to 1% or 2% as this s not your system disk.


Huh. After some digging, it seems that patches to make it work exist (see the linux-usb mailing list), however these patches have not been committed to 2.6.35.

v6 of the xhci pm patchset is the newest, if anyone cares.

Goddamnit Linus.

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