Recently, there was an assertion erroneously made by myself...regarding transfer speeds of external hard drives compared to drives directly attached to the motherboard or to a PCI controller card.

Appreciate any inputs which clear my cobwebs.

I stated that data transfers using an external hard drive (either PATA or SATA) would be slower than such transfers done with the drive connected internal to the computer case. Although I really had in mind something else (data transfers between systems on a home network), my error has prompted me to do a little more reading.

Result? I now think that I was correct, if erroneous in my thinking ...I don't see how a USB bus allows for faster processing of data from a hard drive that is either PATA or SATA...than a PATA/SATA hard drive connected to the system bus.

I don't know enough about eSATA to include it in my analysis, but I encourage inputs about eSATA as well as my focus on internal vs external.

The logic problem that I have is...an external drive is ultimately going to be limited, not by the USB bus, but by the native abilities of the drive in the enclosure. At least, that's what I think.

Which means that a SATA drive will always be faster than a PATA drive...and a SATA II drive will always be faster than a SATA drive...and eSATA seems to be faster than both.

All comments appreciated, thanks . Technical jargon is acceptable .

I found a hard drive chart that may be of interest to some: http://www.tomshardware.com/charts/hard-di...rmance,658.html

Louis

Actually, you are right, but the reason is that the USB controller regulates the speed, and is much slower. The bus speed of a USB 2.0 is 480Mbps, but the controller will be much slower.

I agree with your assumptions. I once had a page saved about various transfer rates. Trying to read it made my brain freeze. Can't seem tp locate it
Here's one:
http://www.storagereview.com/guide2000/