USB 2 Transfer Rates

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Hi,

I need some information regarding USB2 Transfer rates.

I have a Macbook Pro, 3 External Hard drives (all USB2) and an LG Ext. DVD Burner (USB2). They all plug into a D-Link USB Hub, that then plugs into one of the 2 USB ports on my MBP. The other USB port on the MBP is taken up by a keyboard (I run the computer lid-closed + ext monitor).

Now, the reason I bought the External DVD Writer is because the Superdrive in the MBP is only a 4x, which is simply not good enough. So the 16x External drive is so I can burn a full 4.7GB DVD in around 5 minutes yeah?

I ordered some Datawrite Titanium 16x DVD-R discs with the drive as well. I have only burnt one thing so far and i wasn't impressed.

Majority of the DVD burning i will be doing will be from any of the external hard drives. The first burn I did with the new drive+disks took around 10minutes (burning a DVD Video TS folder in Toast). I was quite disapointed as i thought it would fly. I am hoping that it is not because the HDD's and the DVD Writer are both on USB2?

Is it possible that i am saturating the bandwidth by reading from the USB HDD and writing that info to the USB2 DVDRW?

When i was burning I had nothing else running that could tax the system?

Ideas? (unfortunately I cannot tell in Toast what speed and how much data is actually flowing through at the time of writing - am looking for a burning app for MacOSX that shows me that).
 
It's 480mb/sec (that's mega-bit not byte). But the actual rate is likely to be lower unless you have a very fast processor. Firewire is faster (although the quoted speed is slower - less processor dependent) and I believe there is a new firewire version that's much faster.
 
As mentioned USB supports RW speeds upto 480MB/s whilst DVD writable speeds only go upto 21MB/s (16x)

The numbers speak for themselves. You wont be saturating the bandwidth between the two devices.

It could be a possibility if the all three disks were being written too or read from at the same time and the processor is under load but youve said otherwise so that solves that problem.

Have a look here for further information.

http://www.osta.org/technology/dvdqa/dvdqa4.htm
 
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