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StrangeQuark
Jun 8, 2004, 08:36 PM
I'm considering buying an external hard drive for my soon-to-arrive PB 12", and I have a technical question. At what point does the 400Mb/s tranmission rate of Firewire negate speed advantages gained through faster spindle RPM? I've been looking at 10,000 and 15,000 rpm drives, but wanted to make sure they will actually offer a benefit over, say, a 7200 rpm. Thanks in advance.

stoid
Jun 8, 2004, 09:35 PM
400Mbit/s far outstrips the speed of any Hard Drive. That can actually transmit about 40MB/s and even a 7200 RPM drives max out around 10-12MB/s so a 15,000 RPM drive would probably be 25-30MB/s at the absolute most. 7200 RPM is plenty fast for any prosumer use. Unless you plan on using it as a LAN server drive or editing HD video, you won't notice much difference, if any, from faster drives.

crazzyeddie
Jun 8, 2004, 10:03 PM
400Mbit/s far outstrips the speed of any Hard Drive. That can actually transmit about 40MB/s and even a 7200 RPM drives max out around 10-12MB/s so a 15,000 RPM drive would probably be 25-30MB/s at the absolute most. 7200 RPM is plenty fast for any prosumer use. Unless you plan on using it as a LAN server drive or editing HD video, you won't notice much difference, if any, from faster drives.

Um, no? My 7200RPM Firewire hard drive gets 36MB/sec sustained. 7200RPM Firewire is basically best you can get without RAIDs or SCSI. Make sure when you buy a Firewire drive that it has the Oxford 911, 912 or 922 bridge in it. The speed of the bridge board (ATA to Firewire) is critical! Also, if you are serious about speed and your computer has Firewire 800 built in, then by all means get it. If you have very very deep pockets, get 2 Firewire 800 drives, and put them both on 2 separate Firewire 800 busses, then RAID them.

For more on drive speed, see this page (http://barefeats.com/hard30.html) and this page (http://barefeats.com/fire36.html).

StrangeQuark
Jun 8, 2004, 10:27 PM
Um, no? My 7200RPM Firewire hard drive gets 36MB/sec sustained. 7200RPM Firewire is basically best you can get without RAIDs or SCSI. Make sure when you buy a Firewire drive that it has the Oxford 911, 912 or 922 bridge in it. The speed of the bridge board (ATA to Firewire) is critical! Also, if you are serious about speed and your computer has Firewire 800 built in, then by all means get it. If you have very very deep pockets, get 2 Firewire 800 drives, and put them both on 2 separate Firewire 800 busses, then RAID them.

For more on drive speed, see this page (http://barefeats.com/hard30.html) and this page (http://barefeats.com/fire36.html).

Powerbook 12", Firewire 400 only. Thank you for the links.

legion
Jun 9, 2004, 02:12 AM
400Mbit/s far outstrips the speed of any Hard Drive. That can actually transmit about 40MB/s and even a 7200 RPM drives max out around 10-12MB/s so a 15,000 RPM drive would probably be 25-30MB/s at the absolute most. 7200 RPM is plenty fast for any prosumer use. Unless you plan on using it as a LAN server drive or editing HD video, you won't notice much difference, if any, from faster drives.

These numbers are all pretty much wrong. 7200rpm drives deliver much better sustained rates and can outperform the FW400 bus.

virividox
Jun 9, 2004, 04:47 AM
right now fw400 cannot be fully maximized to its 'theoretical limits' just as fw800 can't

just remember the slowest part of your system will dictate the speeds it transfers at; so it doesnt matter if you have a fast external, if you internal is slow then u can only go as fast as it can

legion
Jun 9, 2004, 08:53 AM
You will never hit the "theoretical" speeds on these protocols. Why.. because those numbers include overhead for the protocol themselves which takes up quite a bit of bandwidth.

The easiest proof that a 7200rpm drive (8MB cache) can outperform the FW400 bus is that when you use a FW800 bus, it pumps out almost twice as much in sustained transfers. Obviously, then, the bottleneck is the FW400. End of story.

see barefeats.com for comparisons on data transfers.