I have a Samsung 103SJ 1TB hdd and swapped it from another computer when I built this one. The drive worked fine in the old pc but now it only runs at 3Mb/s when I transfer files off it to any of my other drives (2ssd's and a hdd). Everything else seems to be ok with the computer and I have looked at the smart etc and all seems ok. Now and again it just seems to freeze up as if its looking for data or waiting for a cache to empty, sometimes it does speed up but only to about 25Mb/s and then only for a couple of seconds. I have tried Crystalmark on it but it just takes forever. I have Ashampoo HDD Control and it says it's ok and should be capable of 3Gb/s which is what I expected and got when it was in my other pc. There are no strange noises or anything like that it just runs damn slow. I have Intel RST and that shows the drive as ok and capable of max speed. I have swapped the sata and power leads and also plugged it into another sata socket on the Mb all without any change. Crystal Disc Info does not give any value in the current mode transfer box but does say sata/300 is supported unlike my other hdd which gives values in both boxes so it is seeing something but not saying what. I have another drive on the way but would like to know if this is dying or just playing possum. Any advice/ideas would be appreciated.