Long term data logging - Sampling every 20 ms for 24 hours

Hello I am using max msp and the sql object described here :

http://ift.tt/1zjepML

I basically want to record an electrical voltage which I have streaming into max every 20 ms for 24 hours so I can play it back at various different speeds. Any idea how much space this is going to use up ? Id like to do this over 8 channels so 8 channels for 24 hours taking a sample every 20 ms - any tips appreciated.