Csound1 wrote:
If it is (as you say) "more like your large files taking a long time to load' how will using a drive that is somewhere between one half to one eighth as fast as an internal (bus speed don'cha know) going to help?
SATA is faster than Firewire 800, only if it's used fully, the read/write speed of the drive is the bottleneck, not the interface.
Firewire 800 would be used more bandwidth with a external RAID 0 with 2 drives because the data path is split to go to each drive. Basically turning a 5,400 RPM drive into a 10,800 RPM drive or a 7,200 drive into a 14,400 RPM drive.
If they add more drives then even faster, but then hit the bandwidth limit of the interface used.
eSATA external drives would be ideal, but the Mac lack a port for that, Firewire or Thunderbolt would be next, but the 2009 Mac lacks a Thunderbolt.
Firewire 800 is next and with a RAID 0 of two 5,400 RPM drives, should be fine as a "scratch disk" for working on files. Lots of photographers and Photoshop types use this, it's all the OP needs really, any faster is a likely a waste.
The only problem is the failure rate for RAID 0's are higher the more drives are in the set, 2x, 3x, etc because the data path is split, one byte to this drive one byte to that drive..
One drive dies and the whole set is gone, all data disappears, so the data on the RAID 0 must be backed up nightly with auto-backup/cloning software when the RAID 0 isn't used.
It's "time shifting" basically, one gets a faster machine in the day and at night the lengthily backup occurs to the more reliable single spindle drive.