USB 3.0 Internal Hard Drives?

bcrady

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Sep 15, 2010
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Ok, so the big one is out and it seems to be making it's way into main stream components. You can purchase PCIe cards that will allow you to take advantage of the new USB 3.0 and you can get external hard drive enclosures with 3.0 connections. Which brings me to my question.
If you buy an external hard drive with the USB 3.0 connectivity? What connection is on the hard drive? Are you getting a sata to usb3.0 swap inside that magic box? or are you getting a USB 3.0 straight out of the hard drive?

If you say you get a sata to usb3 then you shouldn't get the usb3 speeds that you wan't because sata isn't as fast as usb3 so there would be a bottle neck right at the back of the hard drive before it ever gets to the usb3 swap. Correct?

If you say you get direct usb3.0 right out the back of the hard drive then yes you will get all the speed that you want and you can go on to transferring huge files just to watch it go. :)

So this brings me to my final point. If they make straight usb3 connections right out of the back of the Hard Drive, why can't I find one anywhere?
I mean they make internal sata drives, why aren't there any internal USB3 drives?
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Little rant below
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If everything went to usb3, and this is just a ramble feel free not to read this if you don't want, but if they made every connection into the new usb3 a monkey could wire a computer.
You could power and transfer data from a DVD,CD,Blu Ray Player with just the one connection.
Same with a hard drive, The way they built usb from the beginning was to carry power as well as data.
Just imagine a power supply without the ominous MOLEX....ewww I shutter just saying the word. But for real, anything that needed power and data transfer could be a usb3. Get your power straight from the mother board, that would take some reworking but I am sure it could be done.
Power a bunch of usb3 headers, run a cable from the header into your drives and there ya go. Power and data.
Whats your thoughts, what angered you, what intrigued you?
Hit me back.
 
USB was never designed as an interface for hard drives, and no HDD's come with USB anything. Any external drive unit that uses a USB connection of ANY type DOES actually have an internal "translation" board that converts the HDD's I/O system to a USB communication system, and the other way. That is one of the reasons that USB2 external HDD's never run as fast as eSATA or as fast as internal SATA II drives - there is a delay in the "translation".

Now, USB3 is MUCH faster than USB2 at its MAXIMUM communication speed. Likewise, SATA 6.0 Gb/s is a much faster communication system than SATA 3.0 Gb/s (formerly known as SATA II) at MAXIMUM capacity. But in any mechanical hard drive (that is, one with spinning disks on a shaft and stationary heads mounted on moving arms), it turns out that the mechanical movements required are much slower than the MAX data transmission rate. Because of this the AVERAGE data transfer rate from (or to) a SATA HDD these days is rarely up to 1.5 Gb/s, the Max data rate of the oldest original SATA spec! There are a few that exceed that, but NONE close to the 3.0 Gb/s spec. Moreover, it is highly unlikely that any such design will get close to the new SATA 6.0 Gb/s spec, or the similar USB3 spec. So for "standard" HDD's, SATA 6.0 Gb/s has NO advantage over SATA 3.0 Gb/s. USB3 DOES have an advantage over USB2 - the new one can match the SATA performance because it exceeds the HDD's capabilities and hence does not impose its own limits.

So why USB3 and SATA 6.0 Gb/s? Because those interfaces WILL be useful for devices faster than mechanical HDD's - the new "Solid State Drives". They are not up to those speeds yet, but they most certainly ARE much faster than mechanical drives already, and probably will gain more. There still might be some issue in the conversion part of the interface. Even if USB3 interface itself is much faster than the HDD inside the external drive unit, the "translator" that must convert between SATA 6.0 Gb/s on the HDD unit and the USB3 system might cause some slow-down.
 
Paperdoc's totally correct - external enclosures have USB 3.0 to SATA converters and the hard drives themselves are just ordinary SATA hard drives. There's no such thing as a "bare" USB hard drive. He's also correct in that hard drives are much slower than either USB 3.0 or SATA and so in performance terms it doesn't really matter which one you use. But SATA does have some advantages not possible using USB such as command queuing, support for extended commands such as TRIM (for SSDs) and for reading SMART data.

SATA is pretty simple to connect - one data and one power connector, and none of the old jumper-setting that was required in the days of IDE drives. And don't think that you can get away with just a data connector for USB 3.0, even for an internal drive. Desktop-class 3.5" hard drives still require more power than USB alone can provide - that's why full-sized external drives in a desktop form factor still need power bricks.

And lastly, USB does not support peer-to-peer transfers so it's not possible to do something like transfer data between, say, a DVD player and a hard drive just by plugging them together. You need a computer in the middle to be a host in order to transfer the data.
 
and this is crazy late for this post but the joke is on you guys USB 3.0 Drives have a direct usb 3.0 I/O straight off the controller with no "translation" board in between like the old 2.0 drives did.... and have been that way since at least 2011