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bwahahax · Jan 7, 2005, 10:09 AM

I am looking at buying another hard-drive for my aging G4 and am wondering if there is a significant speed difference between installing a drive internally through an Ultra ATA/66 connection, or hooking up an external drive that would connect via Firewire. My friend has an Ultra ATA/33 and is also curious as to the speed differential.

If anyone knows anything about this, any info would be greatly appreciated.

Thanks.

Luca Rescigno · Jan 7, 2005, 10:58 AM

Ultra ATA/66 has a maximum transfer rate of 66 megabytes per second. Firewire has a max transfer rate of 400 megabits per second, which if you divide by 8 bits per byte gets you 50 megabytes per second.

I haven't actually compared the three performance-wise in real world tests, but those are the official figures. However, I did at one point have a G4 with two 7200 RPM hard drives on a single ATA/66 bus. Drive-to-drive copies were somewhat slow but overall I wasn't that disappointed with the drive performance.

tooki · Jan 7, 2005, 12:23 PM

ATA has less overhead than FireWire (which is a higher-level protocol), and the data doesn't have to go through as many "layers" of hardware and software. The internal ATA drive will be faster.

tooki

bwahahax · Jan 7, 2005, 04:18 PM

Thanks a lot. You folks have been ever so helpful!

Severed Hand of Skywalker · Jan 7, 2005, 04:53 PM

Originally posted by tooki:
ATA has less overhead than FireWire (which is a higher-level protocol), and the data doesn't have to go through as many "layers" of hardware and software. The internal ATA drive will be faster.

tooki

If you hook up a firewire drive/computer and camera together doesn't it copy the data straight from the camera right to the hard drive for increased speed?

tooki · Jan 7, 2005, 05:53 PM

Umm, no.

tooki

bradoesch · Jan 8, 2005, 07:31 AM

Originally posted by tooki:
Umm, no.

tooki

Severed is partially right, since it is possible with FireWire to skip the computer entirely.

tooki · Jan 8, 2005, 09:23 PM

You are correct that FireWire (as a technology) does not require a host computer, the way USB does. FireWire does allow a host computer to be used, and on Macs, this is how it's done.

However, I am 100% correct that you cannot just take a hard drive and connect it to a camera and transfer the video. That only works with special devices that coordinate the transfer.

But that's not what the question was. The question was whether the computer allowed the camera and drive to communicate directly. The only answer to this is no. The computer is the host, and the data first flows into the computer, and then flows back out to the drive.

You have to remember that the drive is formatted: to do a direct transfer, the camera would need to be able to mount the drive. First, it would need to know how to do that (cameras don't), and second, it couldn't mount the drive because the Mac already has -- it can't be mounted twice.

The direct transfer devices basically mimic the computer, and do know how to mount the disk, but the drive can't be mounted on the Mac at the same time.

tooki