Hey guys, I purchased a used mid 2015 15'' rMBP (still under warranty). I ran some speed tests on SSD. I seem to be getting in the range of 730mb/s for both read & write. Isn't this slow? I was under the impression that mid 2015 mbp ssd is twice as fast as what I am getting. SSD size is 512 and processor is 2.2Ghz. I am paranoid that the previous owner may have swapped the SSD with an older version of it. Any feedback would be appreciated, thank you.