flash drive
I have Mac pro 15. 2011 .Can I use on my computer flash drive 3.0 and I have this port or not?
Only the 2012 mac products have the USB 3.0 ports. So if your mac is 2011 it will not have the USB 3.0 port and therefore will not support it.
http://support.apple.com/kb/HT5172
If you look on that article, you can see the 'Products affected' at the top are all the 2012 models.