| Guys,
I remembered that I had an 2.5 inch laptop drive and a USB 2 enclosure so I did some testing using Xbench and this is what I found (all figures are averages of the read and write sequential tests):
Internal drive: 22 MB/sec
Samsung USB drive: 19 MB/sec
20GB Laptop USB drive: 16 MB/sec
Now here is the odd thing when I connected the 20GB laptop drive BUT it WASN'T being used the speed of the Samsung external drive dropped to 17 MB/sec. Hmmm!!!
Running Xbench on the Samsung drive when the 20GB latop drive was copy 3GB of data to the internal mac drive yielded 13 MB/sec.
So clearly the speed of the Samsung USB 2 drive dropped from 19 to 17 MB/sec when the other USB drive was connected and from 17 to 13 MB/sec when the second drive was in use.
The CPU usage was marginal (< 10%) during all the tests.
According to Activity Monitor the Peak transfer rate for the system was 30 MB/sec during the loaded test.
Conclusions anyone?
Thanks,
Gary |