MBP system reports 2 disks while About this Mac->Storage shows one HD? MacBook Pro mid 2010 system reports 2 disks (320G and SSD) while About this Mac-> Storage only shows one disk. This Mac -> Storage shows only one disk: 320G. I have tried to use diskutil list, it shows two disks as well.

Wonder what causes the different disk configurations?  MBP runs normally. Should I care about the difference?

Furthermore occasionally the Storage shows two disks, (not sure when), including 320G and the SSD, then the MacBook Pro crashed very often, say, every 15 minutes. 



Please help and thanks a million.
You clearly have two separate devices: one a 5400rpm rotational hard drive, and the other an 'after-market' Intel SSD of 160 Gb.

There's limited space in an MBP, so is it possible that your optical (DVD) drive has been replaced with a housing for an SSD?

If you set Finder preferences to show hard disks on the Desktop, does the SSD show up?

Crashes could be caused by a defective SATA connector, either to the SSD or to your hard drive. These parts are known to fail: you can buy replacements very cheaply. If the connector to the SSD is failing, that might also explain why it's missing.

With a 10-year-old mechanical drive and a possibly failing connector to a third-party SSD installed in the optical drive bay, you might want to open it up, replace the hard drive with a new, large-capacity SSD, and investigate any physical problems with the existing SSD and housing.