Hi i am thinking of buying the Raptor X 150GB to use as an eksternal (via FW800) scratch disk for photoshop.
First of.. would there be any benefit in having an eksternal FW800 harddrive as scratch disk?
second..would i experience any perfomance increase using the raptor over any other 7200rpm harddrive when running it via FW800?
My computer is the new Imac 2,8 GhZ with 500GB 7200rpm Hitachi HD and 4GB of Ram
External as in USB2.0 interface? You're better off with generic external storage (USB2.0) from Western Digital and Seagate to name a few. Can't you install a Raptor X in your system to connect with SATA for faster performance? If you're using FW800 then you should go for raid 1 for performance and security. That means two Raptors minimum for the sync operation.
No not usb2. Would connect only via FW800. There is no option for eSata unfortunatly (Mac dont leave a lot of room for messing around when buying their consumer products). As for setting up Raid my budget dont really allow that at the time.. maybe at later time. I quess my real question is: Will there be any performance change running an 10000 rpm drive via FW800 as opposed to a 7200 rpm drive.
Well, theoretically FW800 is 800Mbps, which is 100MB/s, but with some overhead. Maybe consider your throuput to be ~80MB/s which is good. But I believe your bottleneck would be your external enclosure. Make sure it's a good one that doesn't bog down the performance of the drive. That's my 2 cents.
After using firewire and usb drives (5400rpm & 7200) I can tell you that the higher rpm drive is a waste. 7200rpm drives far exceed "real world" firewire output, so the faster drives are a waste of money - if you want fast (sorry 'bout this) try a PC. Then you could use eSata (and have a cheaper, faster rig, as well!).
Think im gonna start out by buying a good FW800 External casing and a used raptor 36GB model and see how it performs.
Photoshop scratch is an application/use that benefits from sustained transfer rate (STR), rather than access time. The Raptor is not a good match for this application. You would be better off with a 7200RPM drive that has a high STR (500GB/750GB/1TB perpendicular recording drive).
If you MUST run the drive in an external FW800 case, then it doesn't really matter anyway. Your actual real-world STR on FW800 is unlikely to exceed 70MB/sec, which is no better than a 2-generation old 160GB drive. You really need to find a way to put the drive internal in your Mac on SATA, get some kind of eSATA interface, or get a SCSI U160/U320 interface.