Lenovo x220 has an internal slot for an mini SATA SSD however this is limited to 300 MB/s while the hard disk bay is provisioned with 600 MB/s bandwidth. mSATA drives are available up to 512GB. The eSATA slot can also be used for a WWAN card.

The X220 has a 7mm drive bay so check the specifications to be sure that the SSD purchased will fit the caddy.

We installed a 480 GB SATA SSD into the X220 hard disk bay. Immediately the machine is noticeably faster. The chart shows the performance is far more than the mSATA port can handle.

With 480 GB, the SSD is significantly bigger than the OEM Hitachi 160GB hard disk. We use a USB 3.0 cable to connect a bare hard disk for backups.

Software to copy the hard disk is readily available. The SSD makes reboots much faster which is very helpful.