What is the point of USB 3.0?

[CKLayoka]

What exactly is the point of USB 3.0? What was wrong with USB 2.0 and eSATA?

USB is used for peripherals like keyboards, printers, scanners. Eventually, it expanded to flashdrives and harddrives. No keyboard or printer could ever use more than USB 2.0 bandwidth.

No conventional hardrive can output data transfer speeds that are greater than eSATA 3.0 gbps. USB 2.0 works great for flashdrives and slower external harddrives and peripherals. eSATA is there for performance-orientated consumers who need fast, large-capacity external harddrives.

The only thing that exceeds 3 gbps (SATA) are very new and expensive SSDs. And SATA 6gbps works fine for that. USB is an external format, and it will be a long time before external 3gpbs+ SSD's become so commonplace that they need their own interconnect.

So why even make a USB 3.0 standard? It simply isn't needed for anything--USB 2.0 works as does eSATA. I'm not trying to sound like a progress-hater, but the entire thing sounded like a marketing gimmick to try an get a whole lot of people to spend a whole lot of money on bandwidth they'll never use and an interconnect that looks identical to the completely-competent USB 2.0. Anyone else thinking like me?

 

[sminlal]

USB 3.0 is needed because:

- It's a *REAL* upgrade over USB 2.0, which is billed as 60MByte/sec but in practice it tops out at about 30-35MByte/sec. So unlike SATA 3Gbit/sec to 6GBit/sec, it actually does make a big difference for hard drives.

- some computers (laptops in particular) don't have eSATA ports.

- it allows for longer cables than eSATA does. This is important if you connect your drive or docking station via a cable that comes from the back of the system and you want to allow enough slack so that you can roll the system out from under your desk without having to undo the cable.

- it allows for faster flash drives.

 

[CKLayoka]

Aright. But wait- you say that "unlike SATA ... it makes a big difference for hard drives" What do you mean? Doesn't SATA make a big difference for drives? I mean, USB 2.0 can be a bottleneck, but with SATA drives the bottleneck is gonna be rpm not the interconnect right?

 

[blackmancer]

No, sminlal is correct.

modern mechanical HDDs are pushing 100MB/s these days and as stated USB2 sucks at about 35MB/s, a backlog of about 65MB/s not being pushed through the port.

 

[panto]

I'm guessing the people who develop USB and SATA are two different groups and each work to improve their products/standards independently. What about USB to devices with storage such as phones, memory sticks, cameras etc? These maxed out USB 2.0 speeds years ago. Also power, USB 2.0 does not provide enough power for .. well a lot of things, I'm sure everyone has experienced this. eSATA in my opinion was just an interim hack to get around the slow USB speeds.

 

[sminlal]

Aright. But wait- you say that "unlike SATA ... it makes a big difference for hard drives" What do you mean? Doesn't SATA make a big difference for drives? I mean, USB 2.0 can be a bottleneck, but with SATA drives the bottleneck is gonna be rpm not the interconnect right?

What I meant is that when SATA went from 1.5GBit/sec to 3.0GBit/sec, it didn't benefit hard drives because at the time no hard drives needed anything faster than 1.5GBit/sec. The latest SATA upgrade from 3.0GBit/sec to 6.0GBit/sec is the same. The bandwidth of the latest version of SATA is really only required for a few of the very fastest SSDs.

On the other hand the upgrade from USB 2.0 to USB 3.0 significantly improves the performance of most external hard drives, especially those in a 3.5" form factor, because they can transfer data much faster than USB 2.0 is capable of. In other words, USB 2.0 is an actual bottleneck for hard drives, unlike SATA 3.0Gbit/sec.

In terms of hard drive performance there's no particular reason to pick one or the other of SATA/eSATA and USB V3.0. The reason to choose USB 3.0 would be because one of the other factors I mentioned above.

Panto - excellent point about the power. That's another advantage of USB 3.0 over eSATA - it provides power to the device so you don't need a wall plug-in. USB 3.0 has upped the maximum power that can be supplied over that of USB 2.0, and so it should be possible to make low-power desktop form factor drives that require only the USB 3.0 connection and no power cable.

 

[buwish]

On the other hand the upgrade from USB 2.0 to USB 3.0 significantly improves the performance of most external hard drives, especially those in a 3.5" form factor, because they can transfer data much faster than USB 2.0 is capable of. In other words, USB 2.0 is an actual bottleneck for hard drives, unlike SATA 3.0Gbit/sec.

I concur. If you have ever tried to transfer a large file or series of files that exceed 1GB or so on USB 2.0, you will have noticed that it takes 3 centuries for the file(s) to make it from your computer to an external hard drive. USB 3.0 changes that though and has lowered such times immensely. Files are getting larger and more portable in today's world, hence the reason for souping up USB speeds- the most common interface on the market today.

 

[jsc]

Plug in a 1 TB USB 2.0 drive with, say, lots of MP3 files. You may as well go outside and watch grass grow while you are waiting for the drive to be ready.

 

[Mimoso]

This is how my external USB drive performs on USB 2.0:

And this is the same drive on the same pc but on a USB 3.0 connector:

Notice any differences?

Sure you can get the same speed with eSata but almost every electronic device has a USB connection these days (not just computers). USB has become the standard for external devices and I really don't need to have different connections for the same type of devices.

 

[RetiredChief]

Concur - USB3 is great, Put a USB3/SATA6 card in desktop and a Usb3 PCMI card for the laptop.

I think all the +es have been noted.
On the USB standard/more common, nah. Most newer computers will have USB3/estata/Sata6 connectivity. Most current laptops are USB2/estata for external conectivity and you can get a USB3 PCMIA card. The advantage over my estata on the laptop is the power issue for My SSD and HDD mounted in an enclosures. USB3 with a combo USB2/esata should start showing up on laptops.

 

[PsyKhiqZero]

Also esata IMO was poorly thought out as it doesn't push power like USB does. infact many laptops have a combo port that can take both a usb or esata cable. these ports are necessary for esata flash drives if you don't wanna have to plug it in to USB anyway. So the need for a faster link that can power a external drive (think portable laptop HDD) is already here.

 

[huron]

Nice data Mimoso...I appreciate it.

I have eSATA and it didn't quite catch on. I'm sure there are lots of reasons, but the interoperability and backwards compatibility of USB 3.0 makes a lot more sense. I will still use eSATA for my own purposes, but I'm sure that we'll see more and more of USB 3.0.

 

[CKLayoka]

Apparently, nobody else was thinking like me. That's ok, thanks for the responses. I suppose you guys are right.

 

[CKLayoka]

Best answer selected by CKLayoka.

 

[jsc]

Mimoso, I knew that USB 3.0 was a great improvement, but this is striking.