just a note; I imagine somewhere there's a list of laptops the system works wells on?   If someone could add the Lenovo W520 to it, that might be useful to others.   I had to disable PCI power management (and CPU power management, as well, but this probably wasn't necessary) in BIOS as related elsewhere on this forum; otherwise, the system would cease working if given a period of inactivity, and require reboot.   With the power management feature(s) disabled, I left it running all night, and this morning it's happy and well.

The Lenovo is a very powerful laptop; can populate up to 16 Gb of RAM easily; and you can swap out the optical drive for a second physical drive; I'm running SSD's in both, and putting all sample data on the ancillary drive; it would seem to be a good choice for running with the ExpressCard setup.