It depends on the sample rate and word length you've chosen. With a totally empty audio file stack, the time available for recording onto the hard disc is (in hours):

Sampling rate 16-bit 20-bit 24-bit

44.1 kHz 5.3 4.3 3.5

48 kHz 4.9 3.9 3.3

88.1 kHz 2.6 2.1 1.7

96 kHz 2.4 1.9 1.6


There's an "HD Free Space" counter on the right hand side of the display that will continuously show you how much time is left at the rate you've selected.