ThinkPad ExpressCache technology and mSATA SSD hard disk drives compared


This document will serve to distinquish between the capability and function of the mSATA hard disk drive (HDD) in current and past generations of Lenovo ThinkPad notebook systems.

CATEGORY 1: ThinkPad T420, T420i, T420s, T520, T520i, W520, L420, L520

ThinkPad T430, T430i, T430s, T530, T530i, W530, L430, L530

NOTE:  W530 models that are RAID capable will not support ExpressCache functionality.

ThinkPads have the capability of adding a mSATA SSD drive into the WWAN slot which will function as a dedicated HDD cache device.  The mSATA drive is used in conjunction with standard rotational HDD’s in order to increase HDD performance.  This functionality is called ExpressCache by Lenovo.  The mSATA drive when used in Category 2 ThinkPads is enabled by the installation of specific Lenovo provided device drivers by Diskkeeper.  The mSATA drive is not accessable as a standard HDD and is not seen in My Computer.


Affected Configurations

The above symptom is associated with, but not limited to, the following systems:

  • ThinkPad

Affected systems:

  • T420, T420i, T420s, T520, T520i, W520, L420, L520
  • T430, T430i, T430s, T530, T530i, W530, L430, L530

Operating Systems

  • Microsoft Windows 7
  • Microsoft Windows 8



The ExpressCache drive has the following limitations:

  1. The ExpressCache drive is not seen as a standard HDD in My Computer and thus will not be accessible or assigned a device drive letter.
  2. The ExpressCache drive is not user configurable.
  3. ExpressCache drive occupies the WWAN slot on the system board thus a WWAN card cannot be used at the same time.
  4. The ExpressCache drive will be visible in Disk Management as a Healthy (Primary Partition).
  5. Installation of Lenovo’s Diskkeeper ExpressCache utility will partition the ExpressCache drive and install the device drivers required for ExpressCache functionality.






Lenovo, ThinkServer, ThinkCentre, ThinkStation, and ThinkPad are trademarks of the Lenovo Corporation in the United States, other countries, or both.

Microsoft, Windows, and the Windows logo are trademarks or registered trademarks of Microsoft Corporation in the United States and/or other countries.


Did this work for you? let us know

  • Alias ID: SF13-T0111
  • Document ID: HT079225
  • Last Updated :17 Jun 2014
  • © 2015 Lenovo