Can anyone test an external USB 3.0 HD to their 2015 MBP using the Blackmagic speed test app? I seem to be mostly striking out in that dept. I can't get anything that has any decent speed. I bought a new PNY 3.0 thumb drive. I get around 120 MB/sec read, but maybe 50 or so write. My WD My Passport drive sometimes goes down to 13 writing, and maybe up to a max of 50. I don't think its the MBP though b/c my MBA has similar results.