This Hardware ID PCI\VEN_8086&DEV_44E that I encountered on the Thinkpad X200 corresponds to the Intel Turbo Memory. The correct driver for it on Vista or Windows 7 (or also windows 8?) is:
I believe this driver applies to a number of other Lenovo Thinkpad models as well.
It is a bit odd that Lenovo does not publish this driver on their driver support site.
This Turbo memory does not work for XP so there is a disabling tool:
Disabling tool for Intel Turbo Memory Driver – ThinkPad R61, T61, T61p, X61, X61s, X61 Tablet, Reserve Edition