Yes it's volatile and the RAMDisk would be the same as anything else in memory, if you crash, what's there is gone....But it's really no different then any other crash, if it's in memory poof, gone regardless. Most RamDisk programs have options so than when you go to shutdown the rig, the data in the RamDisk is saved to the the hard drive and reloaded when you boot, so if you've say loaded programs in the RAMDISK they will be available when you reboot, if you are using large data files files you should be saving them occasionally to a regular harddrive anyway, so at any given time your loss would be minimal - it not something that everyone would like/use. Another thing is that if your system is good and stable, it's not likely to crash anyway. Proper use and taken precautionary measures (which should always be done anyway when using systems) will cut the chances of any but small losses of data