SATA claims 'Up to 300 MB/s SATA transfer rates'
I understand that the hard drive's RPM, buffer, and read/write speed all relate to how fast you can get data to and from the hard drive. But I was wondering, when it comes down to it, what is the rate limiting step in the whole process for an external hard drive?
For example: Is a 7200rpm drive actually faster than a 5400rpm disk when connected by USB 2.0? Or can the USB 2.0 handle nearly any data that the hard drive can send through it?

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