Apple Logic Pro /LogicExpress Discussion

GAmoore@... <GAmoore@...> wrote:

>: Regarding sustained rates : Wouldn't you get more throughput if you had two
>: drives hooked to firewire - so that the delays in head repositioning on one
>: drive allow the bandwidth for the other.

From: amgmamgma <agreenbu@...>

>Well, the drives won't coordinate their efforts exactly, but sure. The bottom
>line is that you won't get more total throughput than the bus allows, so
>the bus will eventually become a bottleneck as you add more devices do it.

That isn't a factor unless you're trying to do something silly like 
record at 192. We don't care about sustained rates or bandwidth, we 
care about access time.

>If I have two drives that are capable of putting out 30 MB/s each, and I
>read from both of them simultaneously at the same priority across 400Mb
>Firewire, the throughput on each will be capped at somewhere below 25 MB/s
>average (allowing for protocol overhead). My total throughput will be
>greater than that of either drive individually, though. You could build a
>RAID-0 array out of external firewire drives and probably get pretty close
>to pushing the max throughput of the bus.

According to Stupid 8-track on the VSL forum, who ran extensive 
tests, RAIDs are actually slower on Macs.
-- 

Nick Batzdorf
818/905-9101, cell 590-9101, fax 905-5434