Re: MSI 990xa gd55 doesn't always detect sata device

Have you checked for firmware updates from Mushkin?
What mode are you running in IDE or ACHI?

http://www.mushkin.com/Digital-Storage/SSDs/MKNSSDCR120GB.aspx

Hmm, have you tried switching the power hook ups if there are extra from the psu? Perhap you ca...