I have a 1.6 TB LaCie that runs internal RAID and is faster than my 500Gig Lacie (72 Mb/sec vs. 52 Md/sec) and have it partitioned as 3 500 gig sectors. I get the beach ball when saving a digitize, where I don't on the 500 Gig drives even though they are slower. All are connected to 800 Firewire and all drives are 7200 RPM. I think it must be something else because my bare 500Gig Lacie is the same size as each partition and I don't have the problem of waiting with the 500's.
Thanks
Charlie
