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Power Over eSATA could replace USB as the port of choice for external drives

Mobile computer users often find that ultra portable computer systems lack optical drives and use hard drives that are smaller than what might be ideal for the sake of portability and longer battery life. Often the best thing these types of users can do is use external optical drives and external HDDs that are connected via USB.

While the USB interface is practical, it isn’t always the fastest interface for transferring large amounts of data. The preferable connection type for moving large amounts of data is via SATA and eSATA ports. These ports are common on virtually all modern computer systems and SATA is used for both storage devices as well as optical drives.

The Serial ATA International Organization (SATA-IO) announced it plans to have a new specification ready this year called Power Over eSATA (PDF) that will provide power to external optical and storage drives via the eSATA connector. The goal of the specification is to not only provide power to a device over SATA, but to maintain the much faster 3GB/s data throughput. SATA-IO says that products using Power Over eSATA could be available on the market by the second half of 2008.

"Its [SATA's] fast transfer rate and efficient protocol makes eSATA the highest-performing external mainstream storage connection,” said Knut Grimsrud, SATA-IO president and Intel Fellow. “Enhancing eSATA with power delivery will provide a new level of convenience to the designer and the end user. By eliminating the need for a separate power connection, customers can more easily expand their storage, making Serial ATA an even more attractive solution for mainstream storage applications.”

With the additional bandwidth and power-over-bus, eSATA could easily replace USB in several applications outside of storage.

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USB 3.0
By TomZ on 1/16/2008 10:14:06 AM , Rating: 3
eSATA + Power will have to compete with USB 3.0 which is currently in development:

http://en.wikipedia.org/wiki/USB#USB_3.0

It has 10X the bandwidth of USB 2.0, backwards compatibility with previous versions of USB, and has power-conserving protocols.

The latter point addresses one of the minor design problems with SATA, which is that it consumes a relatively large amount of power.




RE: USB 3.0
By kelmon on 1/16/2008 10:47:27 AM , Rating: 2
I have to confess to favoring FireWire over USB for external storage devices since the real-world performance tends to be much better. USB's theoretical maximum throughput is definitely higher compared to what you actually get to the point that even basic FireWire 400 is faster than USB 2.0. It will be interesting to see what USB 3.0 really delivers but I'm skeptical for the moment as I don't honestly believe their numbers.


RE: USB 3.0
By noirsoft on 1/16/2008 11:14:44 AM , Rating: 2
The problem with Firewire is that most if not all PC manufacturers only put 4-pin firewire ports on laptops, which do not provide power. Not Firewire's fault, to be sure, but still a good reason why many prefer USB devices.


RE: USB 3.0
By kelmon on 1/17/2008 2:44:00 AM , Rating: 2
That I can understand and it's obviously the manufacturer's fault for being, well, cheap. Without using FireWire on a "normal" PC it is hard for me to comment further beyond to say that I can use my LaCie hard drive with my MacBook Pro with just the FireWire cable but my father, who bought a relatively generic PC, needs to use 2 USB ports to power the Maxtor OneTouch Mini that he acquired at Christmas. Both drives use a 2.5" hard drive so I was honestly shocked that Maxtor needed to use 2 USB ports to draw enough power (well, Maxtor calls the 2 plugs Data and Power). In retrospect we did not try to use the drive with only a single plug but then this isn't the sort of thing to experiment with if the drive is supposed to be containing backups of your important data.


RE: USB 3.0
By Visual on 1/16/2008 12:41:08 PM , Rating: 2
most pcs have just a single (if even that) firewire port though, and while there might be splitters or hubs available (i don't know) that is a bit inconvenient. usb ports on the other hand are already plenty.

either way, usb was meant for low-bandwidth applications, and something new like esata is really needed these days.


RE: USB 3.0
By TomZ on 1/16/2008 1:05:19 PM , Rating: 1
quote:
usb was meant for low-bandwidth applications

Incorrect - 480Mb/s (2.0) and 4.8Gb/s (3.0) is hardly "low-bandwidth." It just happens to be that SATA is currently faster, until USB 3.0 comes out.


RE: USB 3.0
By Visual on 1/17/2008 6:27:18 AM , Rating: 2
3.0 doesn't exist yet, 2.0 is obviously lower than a hard drive so not enough for storage. also, on many implementations this figure is the total combined bandwidth for all ports on a controller, so individual devices get even less bandwidth.
and when i said what you quoted, i wasn't even referring to a specific figure - just the original purpose of the usb bus.
it was meant for your mouse, keyboard and joypad, a printer/scanner and low-res webcam, and definitely not for fast removable storage. it was intended to replace the lpt, com and game ports, not the ide controller on your mobo.
even though the second version made it somewhat more adequate for external storage, it is still not enough, and the original purpose of the bus is still more obvious.
as to version 3.0 - we'll see if it is as good as promised. i certainly hope so


RE: USB 3.0
By dcalfine on 1/17/2008 12:26:25 AM , Rating: 2
I'm going to go ahead and agree there. I don't want to launch a USB vs. FireWire war (especially in a thread devoted to eSATA) but the latter really has a great architecture. The next revision of the IEEE 1394 standard will reach 3.2Gbps and maintain bus power (which, currently, allows a much higher wattage than USB and allows for the daisy-chaining of devices.)

For some reason eSATA always seemed awkward to me. I made the jump from PATA to the recessed connectors of the Mac Pro. It seems flimsy and cheap, though I'm well aware of its technological advantages.

What about networking over eSATA?


RE: USB 3.0
By gramboh on 1/16/2008 11:18:25 AM , Rating: 2
I wonder what the overhead will be like with USB3. With USB2, although the theoretical max is 480mbit/s (60mbyte/s) I never see over 30-35mbyte/s using an external drive in a USB2 enclosure (7200rpm). Using eSATA on a similar drive I see the same transfer rates as using the drive in my PC (almost double). I assume this is because of interface overhead.


RE: USB 3.0
By Ray 69 on 1/16/2008 4:59:08 PM , Rating: 2
If I'm not mistaken, the theoretical max of 480 Mb/s is actually 48 MByte/s not 60 MByte/s. I know that a byte is 8 bits but USB is a serial connection so you would have to add 2 bits to your calculation, a start and stop bit (same applies to SATA connections). Still though you seldom see it near the max except for the rare burst spike.


RE: USB 3.0
By TomZ on 1/16/2008 5:42:08 PM , Rating: 2
For USB, the overhead is actually quite a bit more complicated than that. The 10-bit rule applies to 8b/10b encoding used for SATA, but USB doesn't use the same encoding. Instead, USB uses different size checksums (CRCs) on different fields within the packets.


RE: USB 3.0
By retrospooty on 1/16/2008 11:49:02 AM , Rating: 2
Not really. all eSATA I have seen have USB2 as well, no reason to think the next gen enclosures wont do the same with eSATA+power and USB3. Both will be around for a long time.


RE: USB 3.0
By Etern205 on 1/16/2008 3:29:56 PM , Rating: 2
What's the point of being faster if it cannot sustain it's transfer rate?

USB 2.0 is 480Mb/s while Firewire A is 400MB/s but
firewire has a better sustain transfer rate than USB which
is why most video editing users perfer firewire over USB.

For eSATA it's indeed faster, but for sustain transfer rate
how is it?


RE: USB 3.0
By saiga6360 on 1/16/2008 8:02:21 PM , Rating: 2
I'm guessing the same as an internal drive, which would be pretty normal.


RE: USB 3.0
By mikeyD95125 on 1/16/2008 10:04:47 PM , Rating: 2
The article says 3GB/s but isn't SATA 3 Gbps ? Hate to be a nitpicker but it is a pretty big difference.


RE: USB 3.0
By dcalfine on 1/17/2008 12:28:56 AM , Rating: 2
no, you're right
3GB/s would be an unprecedented feat.


RE: USB 3.0
By B166ER on 1/17/2008 2:19:51 AM , Rating: 2
Not at all nitpicking. The confusion between MB and mb is a huge deal in my book. Its unit of measure and can create a bit of war if not understood. Imagine your ISP selling 6MB/s cable, and you getting 6mb/s? Get what you pay for? To this day I still see hardware sellers, network companies, even the occasional "computer guy" screw this up to almighty hell. Funny thing is, when I comment on its incorrectness, I'm lamblasted for being picky. Go figure.


Question
By BansheeX on 1/16/2008 10:57:20 AM , Rating: 2
Can someone explain to me why we need two different formats for external devices and internal ones? Why not just have USB 3.0 for everything?




RE: Question
By masher2 (blog) on 1/16/2008 12:27:00 PM , Rating: 2
Probably for the same reason shoe stores sell more than one size. No one interface is good for the wide range of possible users and usages.


RE: Question
By TomZ on 1/16/2008 12:39:51 PM , Rating: 2
I disagree - the proposed USB 3.0 would meet most/all of today's known requirements for a serial interface. It would do anything that eSATA and FireWire can currently do, and be faster at the same time.

And I think having a single port standard benefits consumers because there is no splintering effect that causes designers to have to "waste" cost and space on additional connection types.

I do recognize, however, generally that competing standards are helping to keep these standards improving.


RE: Question
By BansheeX on 1/16/08, Rating: 0
RE: Question
By TomZ on 1/16/2008 2:36:47 PM , Rating: 3
I don't know - the ratings are kind of crazy here lately. I see lots of crap posts that don't get downrated at all, and I also see benign posts like yours that do get downrated. Go figure.

At the end of the day, the ratings are a popularity measure, so if you think of it that way, you might be able to figure out how to get higher ratings - or conversely avoid low ratings.

...or you can just say what you feel and don't worry about the ratings at all.


RE: Question
By masher2 (blog) on 1/16/2008 3:21:01 PM , Rating: 2
I wasn't speaking in particular of SATA vs. USB, but rather the general idea that "one size fits all" in the way of expansion ports. Certainly USB and, say, Fiber Channel, fill different market segments and have very little overlap.


RE: Question
By TomZ on 1/16/2008 4:30:58 PM , Rating: 2
Yes, fair enough. I was mainly thinking of the set of USB, Firewire, and eSATA, which I think all address roughly the same set of use cases (except for eSATA which is limited to drives). I'd like to see just one of these three survive.


RE: Question
By spartan014 on 1/17/2008 1:43:44 AM , Rating: 2
Just one doubt..

Which will be able to output the maximum power?

USB 3.0 or SATA-IO or next Firewire revision ?

I think that will be an important factor..


Convenience or Inconveience?
By LTG on 1/16/2008 11:53:27 AM , Rating: 2
This is yet another port type to clutter up our laptops and desktop motherboards, and make them obsolete.

I'd really like to know why USB 3.0 couldn't have been made to provide the same benefits.

This reminds me of HDMI vs. DisplayPort.

LTG
www.hdgreetings.com




RE: Convenience or Inconveience?
By TomZ on 1/16/2008 12:33:32 PM , Rating: 2
I agree with you, the "inconvenient truth" is that a single type of serial port that meets most everybody's requirements is the most convenient option for users. That allows limited space in laptops to be dedicated to delivering more port instances, instead of more port types. So I personally hope that USB 3.0 is successful in getting done and out there.


RE: Convenience or Inconveience?
By jconan on 1/28/2008 1:47:06 AM , Rating: 2
It's a good thing that most people haven't got a macbook air otherwise it would drive a person mad having if the next relase of mackbook air had usb 3.0 since the internals are based on intel chipsets. Technologies good but sometimes its nice to know that what you purchased today won't be outdated tomorrow relatively soon like a non 3g iPhone. Hopefully macbook air will be updated later at the end of this year or next.


not sure it's a good idea
By sdifox on 1/16/2008 11:32:58 AM , Rating: 3
I like the fact that external drives have their own power supply. With today's crazy power requirements on the mb, I don't see why we should add more power problems to it by powering external drives.




eSATA
By dmoney1980 on 1/17/2008 1:01:31 AM , Rating: 2
I'm not here to to argue about whats better (eSATA/USB3, etc.).I do support eSATA and hope it becomes the standard for external devices, but does anyone here know if they make sata cables that are more flexible ? I find sata cables to be quite stiff, and external devices usually need cables that are flexible/bendable.




Should've been there in the first place..
By Mudvillager on 1/16/08, Rating: -1
RE: Should've been there in the first place..
By KernD on 1/16/2008 10:19:56 AM , Rating: 1
SATA was designed for internal drives, there is no need for power over SATA for internal, so no it shouldn't have been there from the start, external SATA is just putting a SATA port at the back of the computer(or front), it was done quick and simple, USB external drive all have seperate power cable, so I don't see why it was a problem for eSATA to do the same. This is just trying to add more feature to compete with USB and FireWire.


RE: Should've been there in the first place..
By saiga6360 on 1/16/2008 10:34:38 AM , Rating: 4
I guess taking out the need for a power cable reduces clutter, especially considering the fact that external drives are clutter to begin with.

Just how much faster can eSATA get compared to USB? I guess it makes sense against an overly saturated USB path but 1:1 I guess it doesn't really matter because the HD drive itself is the bottleneck.


RE: Should've been there in the first place..
By dblind1 on 1/16/2008 10:49:16 AM , Rating: 4
quote:
Just how much faster can eSATA get compared to USB?

Well, it is a lot faster! Max bandwidth on USB2 is 480 Megabit/sec (not Megabyte). So you can get about 60MB/sec over USB theoretically. eSATA is 300MB/sec max although most hard drives usually transfer 60-100MB/sec in the real world. But as you can see, there is a big difference in bandwidth. T

As far as the power over eSATA, it is a lot easier to just hook up one cable instead of having to crawl under a desk to find a power outlet just to find out the surge protector is full. My office for example, I have 3 monitors, 3pcs, usb hub, speakers, etc all plugged in to the outlets close to my desk. If I want to use my usb hard drive, I have to stretch a cable across the floor and over my desk, then put the drive in the middle of my desk so the USB cable will reach my USB hub. Bus power rules.


By diego10arg on 1/16/2008 5:09:35 PM , Rating: 2
Maybe a mix of them could be great. I mean, use your eSata as data-connector and USB as power-supply. Then again you end up having several cables to hook-up.


RE: Should've been there in the first place..
By Mudvillager on 1/16/2008 3:58:30 PM , Rating: 2
I was talking about eSATA...


By KernD on 1/16/2008 7:15:22 PM , Rating: 2
Yep, I know, but like I said, they just took the internal and just called it eSATA when they put it outside. And also like I said, the competition in external drive all needs power cable, so it was no big deal, and it's not like it's cable clutter, your computer screen sits on your desktop and also has 2 cable, at least the external drive is not always there to take up space.

I'm not saying it's not a good idea to have power in the communication wire. I'm just saying people will complain until they have all wireless, including power...


"A politician stumbles over himself... Then they pick it out. They edit it. He runs the clip, and then he makes a funny face, and the whole audience has a Pavlovian response." -- Joe Scarborough on John Stewart over Jim Cramer











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