http://web.ncf.ca/nashjc/USBtimes/usbtimeJN.xls gives some timings I ran yesterday to see if the $8 Blackweb 32G USB3 flash drive at Walmart this week is genuine or flakey. From the timings seems not too bad. The variations over machines and connectors is a bit of an education. Also my oldest laptop had the best USB2 time on one device. I believe I used sync correctly to avoid timing just memory transfers. I won't claim that my effort was perfect. Script below is what I used. Best, JN #!/bin/bash # usbtimer.sh ## run as root so buffers can be cleared ## ?? how to check $1 if [ -d /media/john/$1/temp/ ]; then echo "We have directory /media/john/$1/temp/ available" else echo "/media/john/$1/temp/ NOT found"; exit fi ## make sure file to use is at /media/john/$1/temp/tmp.iso if [ -f /media/john/$1/temp/tmp.iso ]; then echo "File tmp.iso available" else echo "tmp.iso not found"; exit fi echo "clear buffers" if [ -f /home/john/temp/tmp.iso ]; then echo "File tmp.iso exists -- delete it" rm /home/john/temp/tmp.iso fi sync echo "Read from USB" >>t$1.txt date >>t$1.txt cp /media/john/$1/temp/tmp.iso /home/john/temp/ sync date >>t$1.txt echo "Write to USB" >>t$1.txt echo "clear buffers first" sync date >>t$1.txt cp /home/john/temp/tmp.iso /media/john/$1/ttt.iso sync # Make sure we count the flush time. date >>t$1.txt echo "Clear the working files" rm /home/john/temp/tmp.iso rm /media/john/$1/ttt.iso To unsubscribe send a blank message to linux+unsubscribe [ at ] linux-ottawa [ dot ] org To get help send a blank message to linux+help [ at ] linux-ottawa [ dot ] org To visit the archives: https://lists.linux-ottawa.org