Daiy chaining a Firewire audio interface + external HDD

[riotshield]

I just ordered a new Macbook and would like to use it for recording on the go. Has anyone run into bandwidth or latency issues daisy chaining an audio interface and an external HDD on the same Firewire port (specifically Firewire 400)? I'd like to record directly to the HDD. If anyone is doing this, what is the maximum number of 24-bit tracks you've been able to record simultaneously? Thanks

[zimv20]

i've gotten 24 track throughput (8 record and 16 playback) @ 96/24 with a g3 ibook (640 meg RAM). the external drive was 7200 rpm and had an 8 meg cache.