G'day John,
dunno whether these are published spec's or somehow measured/estimated, but the 600 Mb/s roughly translates out as 75 MB/s and of course the 100MB/s exceeds this - both significantly larger than the 1.2 MB/s you've estimated is necessary for the song (there'll be other things going on too to increase this).

There are other factors involved. One is a question as to whether these figures are sustained or burst. Another is what effect associated hard and software may be having - not to mention what problems may be caused by the overheat.

--=-- My credo: If it's worth doing, it's worth overdoing - just ask my missus, she'll tell ya laugh --=--
You're only paranoid if you're wrong!