March 04, 2010, 1:30 PM —
Up-to-date computers now include external ports that, in theory, can handle data at rates of up to 5 Gigabits per second. But which is better?
If you've been in the computer business for any length of time you can probably painfully remember when serial RS-232 ports could barely handle 28 Kilobytes per second. And, adding insult to injury, the standard was loose enough that you could have 'compatible' devices that you could never physically connect. How things have changed! Now, eSATA can handle 300 MBps (MegaBytes per second) and USB 3.0 can wheel and deal up to 625 MBps.
So that makes USB 3.0 better right? Well, while USB 3.0 is good, it's not as simple as "Whoever's the fastest wins." Let's take a closer look at these new and improved ports on our PCs.
ESATA (External Serial Advanced Technology Attachment) is the external version of the technology, SATA, that your computer is likely already using for its hard drive. While SATA and eSATA are both older than USB 3.0, its proponents would still claim that it's better than USB 3.0.
They can make this argument because the most common use for eSATA is for external hard drives. Internally, these drives are still using SATA even if you're connecting to these devices with USB or FireWire on the outside. Thus, the argument goes, these devices must use a bridge chip to translate from the ATA protocol to USB or the FireWire IEEE 1394 protocol.
There are two ways to do this. The first is to encapsulate the SATA protocol-borne data into USB or FireWire. The other is to actually convert the data into one of the external data transmission protocols. In either case, this requires extra steps and processing, which slows down the effective throughput.
Various benchmarking tests support this claim. In particular, eSATA has clearly been shown to be faster than USB 2.0.
That was then; this is now.
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