How reliable are Flash Drives?

Well the flashdrives will fail eventually (I have never had one fail on me thou). I always make a copy of all the critical data and burn it all onto a CD regularly anyway. Your generally ok as long as you have 2 or more copies of the data.

Windows Vista now has the option for you to plug a flashdrive into the USB slot and use it as a cache for the hard drive, so they cannot be that unreliable.

I am sorry, I forgot to state that to be properly protected against the "NAUGHTY" viruses you need to be kept updated regularly. "REGULARLY" depends on the release of updates from the anti-virus software website. I stand "CORRECTED".

Flash memory is much more reliable than a mechanical hard drive. But, it's prone to the same kinds of failures as any other electronic device - ESD, misapplied voltages, dropped in toilet, etc.

Plus, some of the key chains are not very sturdy. My old one fell off at work, fortunately I had some pictures of myself on it so it was quickly handed back (before I even noticed it was missing).

I guess how fortunate that would be depends on the pictures...

Let that be a lesson to everyone. Be careful what you keep on you flashdrive, or at the very least, make sure it cannot be traced back to you (ie- no incriminating pictures of yourself).

This wasn't the direction I expected the discussion to take. But thanks to all for the comments.

It's like trying to herd cats.

All work and no play is dull.

Before After

My family has been herding cats for three generations...

Where do you get the tiny Border Collies?

From accross the border, of course!

Light years better than floppies. (MS seemed to had a vendetta against floppies.

I use my flash/mini HD as the main with copies at home, office, site,

Why not build computers with flash drive technology instead of hard drives? $ must be a consideration but the cost is coming down. I just bought a 4 gig flash for $40.00.

They already do, but would you pay twice as much for a laptop just to have a flashdrive instead of a hard drive?

Flash drives are so cheap now ( http://www.7dayshop.com/catalog/product_info.php?cPath=777_6&products_id=101138 ) why not just buy 2? I carry one with me & keep one at home as a back up with the same data on both.

Got new computer with internal USB port for flash drive. Also seen 12 gig flash drive.

I think they work well to back up a computer. Some of the large flash drive have password protection.

How about a 192Gb USB flash drive with a 7 year warranty http://www.everythingusb.com/simpletech_zeus_solid_state_drive.html (no mention of the price though).

The 12 Gb was about $200.00 but that was couple months a go.

One limitation I have read about in technical write-ups (but have not experienced myself or heard any anecdotal evidence of) it flash memory will degrade over time if not plugged in periodically. No specific time frame for this effect was given.

They are pretty robust.

One of the computer magazines in Australia tried to destroy some as a reliability test. They got to the end of their tests without any real failures (I suppose they crushed on in a press, but that does seem an unlikely event in everyday life). Finally when they had almost given up, sitting in a pub, bemoaning the lack of significant material to write their article, one of the authors said, "wonder what happens when you drop it in your beer?" They finally managed to kill one of their flash drives.

I left one in the pocket of my trousers as it went through the wash. Sat it in the sun for an hour to dry out then plugged it in and kept going. No lost data. Does that say something about the drive or something about the washing powder?

Greg

I've read a couple of reviews on flash drive (FD) replacements for hard drives (HD). Aside from the eventual deterioration of the memory (limited read/write cycles), FDs have slower access times than HDs which translates to lower performance for your PC. I, too, had though of replacing my HD with FD but decided not to after reading the reviews. The technology needs to improve a bit before I do that.

I for one have had a different experience with flash drives; they save data to a point and then refuse to save despite not having filled the memory space. At this point all new data saved on the flash won't stay but old ones will remain.

iInfact its really a pain if you are doing lots of information download and find in the end you have been waisting your time. I suggest you check flash content every now and then as you download, backup etc to ensure all its contents are coming in smoothly.

I have had a few fail, they would no longer read - claiming they were unformatted, sometimes reformatting would give me half or less of the full capacity (e.g. 16 of 32Mb) The USB connector pins became unsoldered on one, from repeated mechanical strain, easy to fix. Another needed one row of pins on the flash chip itself resoldering.

This was a 5/6 years ago now, with cheaper drives. My Corsair Flash Voyager is fast and has been 100% reliable. I copy all the data to my home PC frequently, but still there is a possibility of an odd file being corrupted and me not noticing, I guess some sort of integrity check would be useful.

My flash drive failed after it fell on the carpet probably due to static electricity.

Outside of mechanical failure ...broken pins, delaminating of connectors, cold solder joints, etc. and a flash is very reliable during its life cycle.

The thing is a flash drive has a fixed life span based on the number of read/write cycles and then you start loosing the use of unspecified amounts depending on where the failure occurred on the chip.

Does anybody remember the Bubble memory? It never took off as a product due to the supposedly high cost of manufacture. There also the problem of the things being near indestructible. A bad combination for the modern business model of disposable electronics.

I remember the bubble memories - but never used one.

I remember bubble memory, but does anyone remember leaf memory? This was the Japanese (Hitachi I think) memory with the organic core (the organic component was from a tree leaf). Toted 1GB per chip in the days of the 486 and early Pentium. I guess it never got out of the lab testing stage.

No, you didn't need to water it.

In real life, the flash memory is less reliable than hard drives, in my experience. The reason is that the flsh memory is much more susceptible to ESD than a hard drive (even and external unit) in normal usage. I've had two fail. Maybe I'm more electrified tahn most...or more careless.

In reviewing my post and noting a couple of overlooked typos...the evidence weighs in favor of carelessness.

Just make sure you don't plug your USB flash drive or even a USB hard drive to a virus infected computer. If you contact viruses through your FD it will transfer the infection to any other computer that you will plug it into. So reliability also depends on how careful you use it. Just make sure you plug it into a virus free machine. And if you think you have contacted a virus from other machine, do sanitize your FD first from the infection before further use to avoid the spread of the virus infection.

Naughty. You should have fully up to date virus protection on the computers you are using, so it shouldn't matter.

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In this day and age, virus protection is a must.

Please refer to reply post #30.

You should have fully up to date virus protection on the computers you are using, so it shouldn't matter

Going off topic but anti-virus-makers are one step (sometimes more) behind the virus-makers.

A new virus has to appear (and therefore infect some computers) before an anti-virus update is sent out. A fully updated computer is not a 100% guarantee that it is safe from infection. I've known people who had too much confidence in their anti-virus software and learned too late about their limitations.

Well my old computer's virus protection update feature failed months ago. Hackers have somehow got into it and are maxing out the resources while it is plugged into the internet. A harddrive format will soon fix that.

Let this be a leason to keep updating regularly.

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Nothing is guarenteed in life except taxes.

NASA likes em. And they buy the best.

There are flash drives on the mars rovers.

I require verification of this fact, since flash has notoriously poor radiation performance.

Recent 'Nova` special cited problem with first Rover 'flash drive full` -
when old files deleted, problem solved.

On second though however I doubt if one could get the kind of gold plated unit that NASA would have spec'd. over the counter.

Found them:

http://www.mouser.com/catalog/630/196.pdf

That's very interesting. There must have been extensive testing to qualify these parts, and redundancy in the design - normally we don't use flash in space.

From the MEMTECH website:

On the AT2500, AT3500 and SC35 series of products, Memtech uses its proprietary Active Remap™ technology to recover failing memory cells. This process is automatic and transparent to the user. If a page in memory fails to erase or program, the entire block is permanently moved to a spare location in memory, and the failing block is mapped out of active memory. Spare locations are selected when the device is first initialized, so there is no loss of user addressable memory. There are 100 spare locations for each 100 Mbytes of memory, so an individual block could fail up to 100 times before the drive becomes unusable, though even then, the data would still be available for reading.

On the Mighty series of products, wear-leveling and remapping is used to handle failed memory locations.

From wiki -

The electronics systems had a layer of silica aerogel used for insulation.

from NASA Glenn Research Center:

In addition, the surfaces of the silica aerogels have been modified with (1) amines that have then been cross-linked with epoxies and (2) olefins, such as polystyrene. Polystyrene, because of its high hydrogen content, has been shown to be an effective radiation shielding material.

So, rugged design, built in error correction and radiation shielding are the way to get flash into space.

I'm glad you made me look all this up!

I'm glad you looked this up too. Maybe I don't have NASA certified FD, but based on the conversations this generated, I believe I can trust these things. As with all computing, backups are essential.

Thanks to all!

Well, I guess for NASA, the advantages outweigh the disadvantages, literally. Flash drives are much, much lighter than conventional hard drives. Every gram of weight saved means more equipment can be carried on the space craft or less fuel for the trip. Then again, the weight saved on flash drives can be used for additional or better radiation shielding around the drives and still have some weight allowance left over for other things.

Further, the rigors of lift off, firing thrusters, or the shock of landing means that solid state memory are preferable to electro-mechanical hard drives.

no figures given for USB drives, this is for a SATA one, by coincidence I was looking yesterday.

Reliability

MTBF 1,180,777 operating hours MTBF for 16GB based on Telcordia SR-332, GB, 25°C EDC/ECC Embedded EDC/ECC, based on BCH algorithm BER (Bit Error Rate) <10^-20 Reliability features Built-in power-up self-test (BIT)
Manual and automatic self-diagnostics
TrueFFS bad block management
Data integrity under power-cycling
S.M.A.R.T (Self-Monitoring, Analysis and Reporting Technology) remote monitoring