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USB2 transfer rate to Ext HD?

PostPosted: Sun Jan 23, 2005 4:01 pm
by Intimidator
I have a WD20 GB HD in a USB2 external case. I was making a backup of my W2K Pro system and noticed that I was only getting 45 to 54MB/sec transfer speed when hooked up to a USB2 port. Why is this speed so slow? I
thought USB2 would provide a greater transfer rate than that.

Please Help!

PostPosted: Sun Jan 23, 2005 4:16 pm
by dodecahedron
i might be wrong, but isn't USB2 480Mbit/sec? which equals 60MBytes/sec ?
if that's indeed the case, then 54 isn't bad.

PostPosted: Sun Jan 23, 2005 5:01 pm
by Intimidator
You are correct....I was not sure how to make that conversion. Why do you divide 480mbps by 8 to get MB/s?

PostPosted: Sun Jan 23, 2005 5:25 pm
by MediumRare
Intimidator wrote:Why do you divide 480mbps by 8 to get MB/s?

1 Byte = 8 bits.

G

PostPosted: Sun Jan 23, 2005 5:41 pm
by Intimidator
That is correct....I just forgot the conversion. Thanks

PostPosted: Sun Jan 23, 2005 7:32 pm
by Boba_Fett
Intimidator wrote:That is correct....I just forgot the conversion. Thanks


Heh, makes you wonder why everyone insists on using bits and bytes to describe the same thing. Also makes you wonder why the hell someone doesn't standardize it.

PostPosted: Sun Jan 23, 2005 8:42 pm
by cfitz
Boba_Fett wrote:Heh, makes you wonder why everyone insists on using bits and bytes to describe the same thing. Also makes you wonder why the hell someone doesn't standardize it.

The bandwidth of a serial bus is traditionally quoted in bits per second because data is transmitted one bit at a time, while the bandwidth of a parallel bus is traditionally quoted in bytes per second because data is transmitted one (or more) bytes at a time. The nomenclature is actually pretty standardized.

cfitz