09-03-2017 09:38 PM
The ThinkPad X220 has a 2.5" SATA drive bay that accepts drives up to 7mm in height.
Currently, the highest capacity 2.5" SATA 7mm-high hard disk drive (HDD) is 2GB and they are all manufactured by Seagate. Models are:
ST2000LM007 - Seagate 2TB Barracuda HDD (5400 RPM, 128MB Cache, SATA Rev. 3)
ST2000LM015 - Seagate 2TB Barracuda HDD (5400 RPM, 128MB Cache, SATA Rev. 3) - newer version of ST2000LM007
ST2000LX001 - Seagate 2TB Firecuda SSHD (5400 RPM, 128MB Cache, 8GB FLASH RAM buffer, SATA Rev. 3)
if you want to go with a lower-capacity 1TB hard disk drive, there are are many models available from Hitachi, Seagate, Toshiba, and Western Digital.
For solid-state drives (SSDs), the highest capacity 2.5" SATA drive that is 7mm high is the 4TB Samsung 850 EVO SSD.
If you would like to go with a lower-capacity 2TB solid-state drive, there are many models available from Crucial (Micron's retail brand), Mushkin, Samsung, SanDisk and Western Digital.