you are currently selling the "Seagate 4TB Barracuda SATA 6GB/s 64MB 7200RPM 3.5" Hard Drive" with the Mfr#: ST4000DM000 Quicklinx: 8KRBCE00
The ST4000DM000 spins at 5900 RPM and NOT as you advertise at 7200 RPM
There is a 4 TB Seagate Hard Drive which does spin at 7200 RPM and that is the ST4000DX000.
The biggest difference between the two drives is that the DX version has five 800 GB platters and the DM has four 1 TB platters. Seagate offers a longer warranty on the DX drives than on the DM drives which have a two year warranty.
DABS is not the only one who wrongly designate the DM as 7200 and Seagate does not mention the RPM on its datasheet. It took me quite a long time to nail this down as a fact.
The ST4000DM000 is in my estimation the superior drive even though it only spins at 5900.
In a direct comparison between the DX and the DM versions (which I drew from a number of different sources and took me quite a few hours to find):
1) The DX drives are only slightly faster at writing than the DM and it would be fair to call the comparison a draw
2) The DX drives are faster at reading than the DM versions.
3) The DX drives run a LOT hotter. The difference is between 20% to over 30% depending on what they are doing. This should make the DM the choice for anyone building up a NAS for themselves.
In fact when choosing which drives to install in a NAS the performance of the Hard Drives is nowadays largely inconsequential. You are limited by the the transfer speed of your LAN. In this case the performance of the DX and the DM drives is identical. The no-brainer choice would in this case be the DM because it runs a lot cooler and its practical life expectancy in a poorly ventilated enclosure is - even if it does only have a two year warranty - longer.