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Planner Dude

macrumors 6502
Original poster
May 31, 2006
262
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People on this site say that firewire is better than usb 2.0. Everywhere else I've heard that usb2.0 is faster than firewire. What's the difference between the two (besides one being created by mac & the other pc).:confused:
 
firewire maintains a constant speed when transferring data. more suited for when a lot of data is transferred for a long period of time. usb is good in short bursts.

plenty of debates across the web. just 'google' it
 
Well firewires advantage is that it can sustain it's speed, while USB will not handle this as well. As such firewire is better.

Here is an example from a Lacie drive (notice the bold):

Specifications:
Capacity : 600 GB
Interface :
- 2 x FireWire 800 (9-pin) ports
- 1 x FireWire 400 (6-pin) port (compatible with iLink, DV)
- 1 x Hi-Speed USB 2.0 (compatible with USB 1.1)
Rotational Speed (rpm) : 7200
Interface Transfer Rate :
- FireWire 800: up to 800Mbits/s (100MB/s)
- FireWire 400: up to 400Mbits/s (50MB/s)
- USB 2.0: up to 480Mbits/s (60MB/s)
Max Sustained Transfer Rate :
- FireWire 800: up to 88 MB/s
- FireWire 400: up to 42MB/s
- USB 2.0: up to 34MB/s

Average Seek Time (Write) : <10 ms
Buffer : 16MB minimum
Size : 1.7x10.6x6.8 in / 44x270x173 mm (HxDxW)
Weight : 5.51 lbs / 2500 g
Warranty: 1 year

If you want more info on this search the forums this has been covered plenty of times. :)
 
The theoretical speed of USB2.0 is higher than Firewire, but that theoretical speed includes the overhead of the protocol.

The explanation I've heard for why Firewire performs better in tests is that the USB protocol was created with slow transfer rates and small files (USB1.1) in mind and that makes it less efficient when transfering large files at a high transfer rate (USB2.0). Firewire was created for high transfer rates from the very beginning so the overhead of the protocol doesn't bog down the real transfer speed as much. I can't really vouch for the accuracy of that explanation, though.
 
Thanks....

it seems that for using a computer as a dvr....firewire would be a mich better option then!:)
 
Planner Dude said:
People on this site say that firewire is better than usb 2.0. Everywhere else I've heard that usb2.0 is faster than firewire. What's the difference between the two (besides one being created by mac & the other pc).:confused:

What you've probably heard is that the theoretical maximum throughput is faster for USB 2.0 (480 megabit/s) vs Firewire 400 (400 megabit/s).

In addition to probably inherent technical advantages firewire has, it seems to perform much faster on Macs than USB 2.0 does. I've done tests with both my Dual 2.0 G5 and my Core Duo imac (just in case intel made a difference), and in both cases, identical file copy tests with identical drives yields approximately double the speed with firewire. This could also be due to a poor USB implementation by apple, (or maybe an exceptional firewire one), or the USB bridge in the drives i tested being less capable than the firewire ones.. But the end result is that firewire is a much better choice for storage on Macs than USB 2.0.
 
I have an external HDD that can use either firewire or USB2. I decided to test to see which one was faster. I transfered a ~5GB file over firewire, and then over USB2. The only difference was the connection. The result: USB took a little over twice as long as firewire to transfer the file. The moral of the story: Don't cheap out on your connections, Firewire is worth it.
 
Firewire also has lower CPU usage, since it requires hardware controllers on both ends (device and computer, or device and device). Not that this really matters these days, since processors are getting so fast.
 
On your computer, almost everything uses (and thus shares) the USB bus (keyboard, mouse, built-in iSight, etc ...) while an external peripheral connected by FW would have almost exclusive use of the FW bus.

Also, Macs can be booted using an external FW drive. Only the recent Intel Macs are able to boot using an external USB drive.
 
It takes me 3 hours to transfer files with USB 2.0 but the same drive only takes 1 hour with Firewire. USB should stand for "Ultimately Slow Bottleneck".
 
BornAgainMac said:
USB should stand for "Ultimately Slow Bottleneck".

Haha. Yeah, what everyone else said about theoretical vs applied and the thing with USB requiring (more ?) CPU time than firewire.
 
It's (consistently) faster, and has higher bandwidth.

An example is: I can stream H264 vid over Airport from FW HD's connected to my iMac to my Macbook/powerbooks with no lag or interruption.

Trying the same thing on my USB2 drive gives me hiccups and usually lag bad enough to crash even VLC.
 
Firewire also provides more power to the bus than USB. Allowing for things such as 3.5" self powered drives. USB=2.5 Watts, Firewire 6-15 Watts
 
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