Replacing USB Drives with eSATA
Yes, you read that correctly. I am posting about replacing my favorite thing in the whole wide world, USB drives! OK. To be fair, I am aiming directly at the larger external USB hard drives because I think that their days are numbered. (My little flash drives, though, are still going to be with us for a long time.)
eSATA is touted as the next product that is going to replace external USB or FireWire (IEEE 1394). Just what is eSATA? Here is what Wikipedia has to say about it:
Aimed at the consumer market, eSATA enters an external storage market already served by the USB and FireWire interfaces. Most external hard disk drive cases with FireWire or USB interfaces use either PATA or SATA drives and “bridges” to translate between the drives’ interfaces and the enclosures’ external ports, and this bridging incurs some inefficiency. In the case of USB 2.0, protocol overhead limits the maximum effective bandwidth to a fraction of USB’s physical signalling rate. With modern hard disk drives, USB’s transfer rate is a bottleneck. FireWire, with its isochronous transfer mode, is more efficient, such that even in its slower variant, FireWire 400 (IEEE 1394a), the effective transfer rate is significantly faster than that of USB 2.0, but this can still be a bottleneck for fast drives or RAIDs. Some single disks can transfer well over 70 MB/s during real use, well in excess of USB 2.0’s or the older FireWire 400’s abilities. Finally, some low-level drive features, such as S.M.A.R.T., are not usable through USB or FireWire bridging. eSATA does not suffer from these issues.
With home networks becoming more common, it is not surprising that a consumer version of externally attached storage standards was developed. Even though the standard has been around since 2004, it is only now that we are starting to see devices being built with this standard in place. And it has a long way to go before it enjoys the popularity that USB and FireWire enjoy. For example, when I searched a popular online tech store for 3.5″ external storage, it had 142 USB, 48 FireWire (400 or 800), and 17 eSATA. I suspect that this will start to change as time goes on.
What I believe will be the major turning point for eSATA is when the ports become standard on motherboards. This will then make it just as easy as USB and FireWire to connect to their systems. Presently, most systems do not come with eSATA connections so this requires either installing a card in your system or using a eSATA converter (either from USB or FireWire) to attach an eSATA device. Unfortunately, installing cards is more than many people want to do so they will go with a USB device that does not require any extra installation and the converter devices generally eliminate many of the advantages that eSATA provide so that removes many of the reasons to go to eSATA.
Here is a nice summary from Wikipedia comparing some of the different ways of attaching external devices:
| eSATA | FireWire 800 | FireWire 400 | USB 2.0 | |
|---|---|---|---|---|
| Speed (Mbit/s) | 2400 | 786 | 400 | 480 (burst) |
| Max. cable length (m) | 2 | 4.5 (16 cables can be daisy chained up to 72 m) |
4.5 (16 cables can be daisy chained up to 72 m) |
5 (USB hubs can be daisy chained up to 25 m) |
| Power provided | No | Yes (12-25 V, 15 W) | Yes (12-25 V, 15 W) | Yes (5 V, 2.5 W) |
| Devices per Channel | 1 (15 with port multiplier) | 63 | 63 | 127 |
5 Responses to “Replacing USB Drives with eSATA”
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Sam Says:
April 20th, 2007 at 9:15 amYeah, I just read an article on Tomshardware.com talking on the same subject. I have to say that eSATA will make a huge difference in both home an business use for data sharing and data backup. With HDD media becoming so inexpensive, data backup solutions should become a norm and adding eSATA will hopefully make it easier and quicker.
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Shep Eddy Says:
April 20th, 2007 at 1:00 pmAside from speed, I cannot see much that will make me run to eSATA. The disadvantages seem numerous. The biggest is YAP (Yet Another Port). We’re finally getting rid of parallel and serial and the other ports as we merge toward a universal USB port. Now, we’re adding more ports.
No power supplied.
Shorter cable length.
Doesn’t daisychain except with port multiplier. A 5 port multipler costs $85.USB may be slow but it sure is convenient. I’ll be the first to admit that I don’t know much about eSATA. But from looking at the specs, I can’t get too excited at this point.
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Tim Fehlman Says:
April 20th, 2007 at 1:52 pmI see this as something that you would probably attach to a home or small office server. I agree that USB is still extremely convenient and everywhere.
But, when speed counts, you sometimes make compromises.
Tim
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Sam Says:
April 20th, 2007 at 4:00 pmI agree with Tim. Here’s a great write up on SATA and eSATA being used for desktop and enterprise use. I can defiantly see it’s advantages. When backing up data, you want your backups quick and efficient. When you need to retrieve them, you need them even faster. For something that isn’t going to be disconnected or reconnected often (external data backup, or storage array), then eSATA is a winner. Configuration is easy, and it’s fast. If you’re looking for a portable solution that you can take place to place, then usb is your best bet.
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CMAC.IN.AFGHANISTAN Says:
April 22nd, 2007 at 11:53 pmhmm esata and usb…
Seems like we’re comparing apples and oranges here. The primary draw of USB would be the fact it is self powered.
External storage is *usually* only used on a mobile platform. I’d put good money no matter how fast esata is vs USB, the masses will still flock to 2.5 self powered external laptop hd’s. Another option in the making is powered USB, but that’s awhile away from taking off (http://adterrasperaspera.com/blog/2007/03/29/why-powered-usb-is-needed-part-1-the-short-history-of-usb/)
but that’s all i got
Jarek
