On Friday, 19 August 2016 4:57:15 PM AEST Piers Rowan via luv-main wrote:
That's a tick over 8Gb/hour, what are you complaining about? :^)
Is that mainly due to the USB2 interface on the PI? And what file system are you running on the USB drive?
$ echo 8000/3600|bc -l 2.22222222222222222222 8Gig an hour is 2.2MB/s. USB2 typically gives about 32MB/s nowadays, strangely in the days when a P3 was a new system it gave about 35MB/s. The USB bus wouldn't be the bottleneck here.
Its an encrypted ext3 drive, which I am sure only adds to the overhead
I just did a quick Bonni++ run on my Thinkpad T420 with a i5-2520M and a 500G SSD that's encrypted. It was giving 417MB/s sequential output and 550MB/s sequential output with 19% CPU use. If the SSD was capable of it then my Thinkpad should have been capable of around 2500MB/s encryption speed! The i5-2520M CPU is a lot faster than what's in a RaspberryPi, but is it 1000* faster? It might be worth doing a Bonnie++ run. Also try running zcav (part of the Bonnie++ suite) to test sequential IO speed without encryption. -- My Main Blog http://etbe.coker.com.au/ My Documents Blog http://doc.coker.com.au/