The Desktop HDD.15 4TB is Seagate's official 4TB disk for use in desktop PCs. Unlike the 7200.14 disks, it runs at 5900 rpm, which means lower performance. The high data-density does make the Desktop HDD.15 4TB somewhat faster than most 5400/5900 rpm disks. Just like the 7200.14 disks, the Desktop HDD.15 contains 1TB platters, four of them in this case.
Any major computer upgrade generally requires a full software reinstall too. No so if you heed the advice in the guide to Upgrading a Motherboard without Reinstalling. PCSTATS Tips