So...Let me start off this New Year 2008 with a rant post.
I am constantly amazed at the technical knowledge of some of the folks manning the shops selling computer peripherals. I was in the market shopping for an external casing for my SATAII HDD and someone recommended for me to use an USB2.0 external interface because, as he simply puts it confidently and points to the marketing material on the box, "it is faster"
I have to correct him that the theoretical speed of USB of 480Mb/s is not faster than the theoretical speed of SATAII, which is pegged at 300MB/s. The astute reader will notice the difference in casings.
A quick glance at this article will show the usual naming and differering configurations and the huge difference between a Byte and a bit.
To do some simple calculations - The max burst transfer rate of SATAII is 3 billion bits per second, which is equivalent 3 Gb/s, via normal conventions not definitions. This is equivalent to 300 million Bytes per second, or 300 MB/s. Some sites like this states 300Mb/s, which actually means we are moving backwards in technology. Worst, some people state it as 300 GB/s, which means I can transfer the equivalent data of 31 DVDs in 1 single second and overstating it by about 1000 times faster than it really is.
The same applies for USB2.0. Many technical sales people I talked to told me its 480MB/s and I have seen the same marketing collateral on the packaged boxes it comes in. In actual fact, it is 60MB/s.
Now, if you compare apples to apples - it is a no-brainer to compare 300MB/s against 60MB/s, isnt it ? Of course, the arguments will always begin when people start arguing whether is it really a 5 time performance difference, taking into account the costs of USB's overheads and the cache memory that some of the higher-end SATAII HDD offers.
Well, lets just leave those arguments in those other blogs and forum posts for now.