On July 2, 2014 2:01:08 PM EDT, Anton Aylward
On 07/02/2014 12:58 PM, Greg Freemyer wrote:
On Wed, Jul 2, 2014 at 12:42 PM, John Andersen
wrote: On 7/2/2014 8:59 AM, Greg Freemyer wrote:
All,
I happened to run a USB3 throughput test recently and it wrote 5 TB in 7 hours. I used a USB3 hub to let me hook up 5 1 TB drives and wrote to them simultaneously.
That's about 200 MB / sec.
It's the first time I've ever apparently saturated USB3. Does anyone know if 200MB / sec is a good max USB3 throughput?
fyi: Per the spec, it should be possible to hit 500MB/sec., but real world seldom hits the spec limits so 200MB/sec may be as good as it gets. If not, I may need to look for a better USB3 hub. (I do a lot of high bandwidth transfers in my job.)
Greg -- Greg Freemyer
Using what method did you write to 5 drives simultaneously?
Something similar to "dd if=/dev/zero of=/dev/sdb" for sdb, sdc, sdd, sde, and sdf individually.
I actually used "dc3dd wipe=/dev/sdb" etc. It is more efficient than reading from /dev/zero.
It was not a broadcast mechanism.
Best I know, is that you can send data to ONE usb device at a time based on the addressing scheme, and sending to 5 required 5 send operations each with a different address.
I did not mean the same level of simultaneous that you are. I meant the data packets were interleaved.
Which is about the worst case you can think of.
Rotating rust can typically only do 100 to 120 MB/sec. with a single spindle. USB3 has a theoretical maximum of 500 MB/sec. Adding concurrent wipes added to the overall throughput from what I could tell. My questions are: - is 200MB/sec a reasonable absolute max. Ie. With 5 drives, each drive was only getting 40MB/sec. Not all that impressive. But with only 2 concurrent wipes, the throughput was lower. - for data transfer from one drive to another, is 60 MB/sec the best I can expect to do? It would be free to get that up to 100 MB/sec. Greg -- Sent from my Android phone with K-9 Mail. Please excuse my brevity. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org