Raspberry Pi 1Tbyte hard drive kit

the-raspberry-pi.html

I don't see how that's much differrent from any USB external drive (except that it comes without a case). 2TB and 3TB drives are available in US under $100.

I can see how you'd set it up as a network drive, but that's not a requirement for me.

Well imho the site is kinda screwy...you can't make a customer account (usa version) till you make an order....so my first order was blind because it looked like it took..but got no confirm nor email nor would it take my info after the fact to log on as it said. Used (amex) verified with amex that it did NOT go thru after 1/2 hr.

So anyway went on did it all again ..this time used PAYPAL with AMEX as my card under paypal ..worked just fine etc

So just in case I'd use the credit card option with paypal to order simply because if it does NOT go thru or whatever you have no way of knowing ...because you can't get a customer account till after your first order

so anyway here is the other thing....seems the USA site is already at 35% special from $79.99 to $51.99 ...tax for your state is added and the difference between GROUND shipping and 2 Day Shipping was

1.00 or 6.99 for 2 day shipping ..so get that imho for the extra buck.

So anyway at least for now (the above special) the code does not work (yeah I'm cheap I tried it)

Lastly, they only allow you an order of ONE ..not that I needed 2 or anything but testing the order box ...would not let me add to box...so you need more at this price....sucker a friend to do so.

Anyway..what happened to me...so again I'd avoid the cc option for now and use the cc option under paypal ...I had no luck at all the first time thru with this screwy site. Just saying :)

(Gonna use the drive overkill thou it may be on my Litecoin Node just to contribute to the Litecoin blockchain network...yeah I need a life) :)

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Thanks for that, James. I've ordered one as well - "just in case".

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Cheers, 
David 
Web: http://www.satsignal.eu

The drive has a USB3 interface built in the disk as opposed to being SATA drive with outboard SATAUSB3 interface.

If it supports UASP then that would be a plus for use on other (non-Pi) USB3 controllers.

As I read it it has a USB3 *cable*. At this point I am not so sure about the drive interface.

I had to look that up. In case anyone else wonders what UASP is I presume you mean

James

If I am seeing this correctly, the power arm of the cable is *very* short, maybe three inches (8 cm). That would make it hard to reach the power brick.

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Rick

I am, there is a USB3 micro B connector clearly visible on the back of disk. You did look at the picture didn't you? Or maybe you could read the quick install guide which shows how it connects. ;-)

Any idea if the USB3 interface is native to the drive or just done with an internal SATA interface and an inboard SATAUSB3 chip? It's not like that wouldn't be the easy route for the drive maker. Are USB3 drives common? If so, I guess USB3 might be done natively.

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Rick

...

Call me a cynic if you like but the presence of a connector does not mean that all the pins are connected and functional. That *may* be the case but the blurb I read did not say that the drive electronics were USB3, only the cable. As the Raspberry Pi has USB 2 there would be no advantage to having any working USB 3 on the drive.

For example, maybe WD made a load of these drives and found that they would not run at USB 3 speeds so they thought they would sell them off as a bundle or kit for something that had only USB 2 support....

James

On 12/09/2015 00:05, James Harris wrote: []

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Actually, when testing with PCs I have found that USB 3.0 devices often perform faster than USB 2.0 devices even when plugged into the sane USB

2.0 port. Perhaps they are faster internally, perhaps there is less overhead in the interface, or whatever. Speed tests can and do show an advantage. Check for yourself.

I've not tested this on the RPi, though.

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Cheers, 
David 
Web: http://www.satsignal.eu

Well given I work for a company that designs USB host and device controller IP, a company that designs and produces USB driver software and I work in the USB IP department on our USB product portfolio, maybe I know something more about USB and this WD drive than you do :-)

I dunno, do you? I see a lot of bluster. Do you know about this drive? Did you work on anything for this drive? I haven't seen you post anything other than that you can see a USB3 connector.

I expect if the drive has a SATA to USB converter chip inside it would be detectable by some method just as you can identify all the USB components in the chain. Am I wrong? Anyone tried this?

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Rick

Well, you could always try tracking down the specs for the drive used. There's a photo of the kit which shows the drive to be a WD10JMVW. There don't seem to be any specs available for the drive itself but it would appear to be the drive used in the 1TB Passport drive.

Wild speculation is always more fun though.

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Mike Fleming

From WD's website

"What It Comes With 1TB Native USB Hard Drive 1 microSD? card with SD card adapter 1 Power Adapter and USB cable 1 USB WD PiDrive Cable 1 Install Guide"

I wont hold my breath for all those without a clue to say "gosh you were right all along".

I'm curious what you think you are right about. I'm not trying to be argumentative. I just don't get what you are saying here.

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Rick

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Do you have a particluar way of doing such speed tests or a certain piece of software that you trust to give good figures?

I ask because I don't think a simple data transfer is enough. IME the speed of a disk varies a lot between outer and inner cylinders. For example,

That particular disk averaged (using long 1-minute averages) about

80Mbyte/s on the outer cylinders and 40Mbyte/s on the inner. So SDTRs (sustainable data transfer rates) can vary by a factor of 2 depending simply on which part of the disk surface is being accessed.

Added to that, short-term averages could show figures significantly higher or lower as they interact with things like the disk drive's inbuilt buffer memory, how a file is laid out on disk (the above graph was from disk-order sector access), other loads, remapped sectors, and drive autonomous operations.

James

James, I use this software - h2testw:

It does large file transfers, but is primarily designed to check that a

32 GB memory card really has 32 GB and is not a remarked rip-off. Quite accept what you say about large versus small transfers, random versus sequential etc.

For HD testing I have used HD tune 2.55, so I appreciate speed the difference between different regions of an HD.

Most of my testing has been with SD cards, and a few USB memory sticks, but moving to USB 3.0 on both device and PC interface has made HD transfers (backups or large Zip files generated nightly on a PC), and SD card reading (out of the camera, getting pictures onto a PC) a lot quicker.

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Cheers, 
David 
Web: http://www.satsignal.eu

If you're testing sustained transfer do it across the whole platter (or at least at the inside and outside). Multiple small or heavily fragmented files will be more affected by seek time, and physical cache may have a major effect on small transfers. I suspect that the way the OS behaves can also have an effect (in addition to its own caching behaviour) but I've never noticed comparison tests that use multiple OSs.

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Mine has arrived. If anyone is interested, initial findings follow.

The new drive is currently sitting underneath the Raspberry Pi going through a read-only badblocks scan. The first 10% of the 1Tbyte drive took an hour so I expect the whole scan to take 10 to 15 hours.

The kit came with a clear instruction sheet and was easy to set up. The power adapter came with slide-on adapters for UK 3-pin and euro 2-pin sockets.

There is a four-way cable which connects USB and power to drive and RPi. Maybe these are standard but, if not, it might be hard to replace if it got damaged.

The drive has a white LED at the back. As with many LEDs these days it is bright enough that I had to turn it away out of sight.

I wasn't sure where a USB drive would appear in the device hierarchy but it showed as /dev/sda.

In terms of performance, if my calculations are right the 2.5" drive is running at about 27Mbyte/s and it was about the same in write mode. While it is scanning the disk the Pi2 CPU is 70% idle and 25% in IO wait. The other 5 to 10 percent is mainly taken by usb-storage and badblocks.

James