External hard drive vs flash drive question

Thread Starter

scythe

Joined Mar 23, 2009
49
I hate using USB flash drives because I keep forgetting them in the USB ports of campus computers after using them. My question is how long would an EHD last if I were rewriting files on it all the time (like daily) and would it take a long time to write? If anybody knows, I'd be very appreciative.

Hopefully, I won't forget an EHD when it's right in front of me, with a cable stringing it back to the computer. We can only hope... :rolleyes:

EDIT: It would be pretty cool to keep your files entirely on an EHD and not on any PC you actually use. But if you were to drop it, or get caught in the rain... I guess you could literally be hosed... lol
 
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Wendy

Joined Mar 24, 2008
22,782
Why not tie a string to the flash drive to your finger or a belt loop, it is a heck of a lot cheaper and more rugged than a hard drive.
 

Markd77

Joined Sep 7, 2009
2,806
Or a USB cable, then you can have the flash drive in front of you, maybe mount it in a bigger box with flashing LEDs.
 

retched

Joined Dec 5, 2009
5,208
Make a USB flash drive belt buckle. keep 6 or 8 feet of USB cable wound in the back pocket (Or use it AS the belt ;) ).

When you sit at the workstation, you plug into the computer, then into your belt.

It looks like you are a spy, and the nerd chicks dig-it. ;)
 

Thread Starter

scythe

Joined Mar 23, 2009
49
lol, perhaps a USB utility belt, fitted with ample ports, blinking LEDs and a push button(buckle) retractable USB extension cord, with an audible voice that says "Please do not forget to secure your hardware. Have a nice day."

lol...

I think we may have something patentable here...
 

SgtWookie

Joined Jul 17, 2007
22,227
I have a number of USB flash drives, but they're all 4GB or less.

I picked up a 1TB (yes, one terabyte) Seagate portable USB drive for about $90 on sale at Best Buy. I am not completely happy with the unit, as plugging it in to one group of USB connectors causes the system to not recognize other flash drives. So, if I want to transfer data between the Seagate USB portable USB to a flash drive, I have to plug one into the rear panel USB ports, and the other in the front panel.

As far as tying a string from the USB flash drive to your belt - rather than that, just attach a large lightweight object to your flash drive so it's more easily spotted. Odds are good that if you use a string attached to your body, you will wind up snapping the flash drive connector off, because you applied force at an odd angle rather than straight back.
 

zero_coke

Joined Apr 22, 2009
294
1 million sure isn't a lot if you ask me...the drive probably gets written to thousands of times per day according to the OP's daily use of it.
 

tom66

Joined May 9, 2009
2,595
SgtWookie, the problem you are describing is common to all high power devices plugged into USB. An external HDD draws a high current in operation because it is spinning media. This means that plugging in other devices will not work, because the controller IC is unable to budget power among the devices... it's either the HDD works, or the flash drive works. I've seen external HDDs which draw upwards of 1.5 amps. Which is actually a violation of the USB standard. When the controller has a budget of maybe 2 amps it is really pushing the limit.

Also,

1 million cycles doesn't sound like a lot.

Until you do the ballpark math.

A typical flash drive has a write rate of no more than 12 megabytes/s, in my experience. If you have a 4 GB drive, you have 34.35 billion bits!! If you were to write each one 1 million times, it would take you 2.7306 billion seconds... that's well over 86 years of continuous use. Even if you were to have some kind of super-speed 60 MB/s flash drive (the maximum USB 2.0 would allow, neglecting protocol overhead), it would take you a good 17 years. It's also far longer than the MTBF of a HDD, or the components inside the flash drive itself like the LED and the USB connector.

Another point, modern flash drives use transparent wear levelling, which basically means they balance writes across the medium, preventing continuous writes to a single sector from rendering the media useless. This is transparent; it is not handled on the filesystem level, but instead by the flash chip.

A good USB flash drive will outlive a hard disk drive any day. Heck, it will probably outlive several. And when your flash drive doesn't want to write data any more, it won't lose the data - you can still read it - unlike a HDD where a failure can be catastrophic.

I bought my 4GB SanDisk Cruzer flash drive for £6.99; a steal, when you realise there are 34.35 billion transistors in it (not including interface logic!) And I've been using it for a couple months with no issues whatsoever.

Price is a factor. I have a 1 TB external hard disk drive filled with media. (It's still only 40% full... I'm actually finding it difficult to fill it up!) An equivalent SSD would cost me on the order of a small used car... Solid state memory is not new; but only recently has it become reasonable to store much on it. I welcome the day when you can pick up a 256 GB SSD for the same price as a 250 GB HDD, but it will take a LONG time for that to become viable.
 
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