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USB Flash Drive Life Varies Up To 10 Times
Lucas123 writes "Differences in the type of memory and I/O controllers used in USB drives can make one device perform two or three times faster and last 10 times longer than another, even if both sport the USB 2.0 logo, according to a Computerworld story. While a slow USB drive may be fine for moving a few dozen megabytes of files around, when you get into larger data transfers, that's when bandwidth contrictions become noticeable. In 2009, controller manufacturers are expected to begin shipping drives with dual- and even four-channel controllers, which will increase speeds even for slower drives."
I assume the article is talking about flash drives. Are there any filesystems designed to specifically target these drives? The drives probably don't include any fault-tolerance, but a filesystem could, in theory.
While technically you are correct, you can assume that both will be affected by how good your engineers are. Well engineered drives will be both fast and have efficient wear-leveling. Poorly engineered drives will be slow and have terrible wear-leveling.
Why is it every other media we have speed-ratings and benchmarks and reviews? With USB thumb-drives you can't tell virtually anything when purchasing one other than what color it is.
I want to know SOMETHING like 133x is defined for CompactFlash to give a basic idea of the speed of the device. I'm willing to accept some fudging around but not prepared to find out my new 32-gig flash-drive is 10 times SLOWER than my old 2-gig one. How has this situation persisted this long in a performance-obsessed technical field?
So, wait. Are you telling me that better quality products will perform better and last longer? You've blown my mind here! My whole worldview will need to be adjusted.
[insert witty quote here]
Then I copied a 700 MB file onto it from a local hard drive in gnome, which reported initially that it was transferring at 20+ MB/s, but that dropped steadily until it levelled off around 6.1 MB/s.
Far from scientific, yes, but I wonder a)why the inconsistencies, and b)how these results compare with other products.
db
I am literally 3000 tokens away from the chaotic crossbow --Stephen
Always, when possible, submit a link to the print version. It's faster, on one page, and gets rid of those annoying frames, ads, etc. that litter most tech Web sites these days.
http://www.computerworld.com/action/article.do?command=printArticleBasic&articleId=9093718
I am literally 3000 tokens away from the chaotic crossbow --Stephen
My biggest beef with flash drives thus far is with the flimsy construction. I have owned three flash drives. The first was a 64 byte drive back in the day when that was sizeable. I think it was an Iomega drive. It was really tiny which is why I liked it. But after only about a dozen gentle insertions (no jokes please), it developed a crack in the housing which soon threatened to cause the whole device to fall apart. Iomega was kind enough to replace it for free (it was still under warrantly, less than 6 months old) with a 128 Megabyte version. That was drive #2. I think I lost that one.
My next drive was a Patriot 2 GB flash drive. It lasted maybe 50 insertions before the usb connector "pushed in" and became so loose that it could no longer be inserted properly into a USB port. I ended up snapping the outer housing off and now it's just a little tiny PCB with chips on it and a USB connector at the end. Works fine but I wouldn't take it anywhere remotely hostile. I keep it next to my computer.
So what is the point of this long story? That flash drives tend to have really cheap construction (in my experience) that doesn't hold up to much use, let alone much abuse. In the case of the Patriot I'm not surprised because it was a really cheap unit. But the Iomega was not.
I don't doubt that th expensive ruggedized flash drives can take much, much more abuse. But they represent like 1% of the market. Most drives are these really flimsily constructed things that fall apart when you look at them the wrong way.
durability has a lot more to do with drive lifetime than the durability of the flash components. I have had 3 memory sticks die, and none of them have been because the flash wore out. One I managed to kick and separated the flash part from the USB connector(which was a bitch to get out of my mac pro), another the USB connector became very flakey right after I bought the thing, it would sometimes read, sometimes not, and the other just stopped working(ok, theoretically that could have been due to flash wear, but the thing was less than a year old). In my opinion, if reliability is a chief concern, get one of the small plastic ones. My little red iMation drive has took lots of abuse, and because it is so small, the odds of a collision are significantly reduced.
Monstar L
I installed Arch Linux on a cheap 2 GB Patriot flash drive. It boots pretty quickly and overall performance seems good, even for a cheap drive. However I don't do hugely disk intensive tasks with it.
/proc filesystem entries to turn more aggressive write cache flushing on. I can't keep up with the /proc filesystem because it changes so frequently, so I don't even bother to try to stay abreast of how to do things with the Linux kernel in this way anymore ...
One annoying thing I have noticed is that programs will periodically completely freeze up and I'll look over and notice that the activity light on the drive is flashing. A common experience is that Firefox will be completely unresponsive, not even redrawing itself when a window that was obscuring it is moved, until the drive stops flashing, and then Firefox will instantly come back to life.
My theory is that the kernel is caching writes to the drive and then at some random point decides it's time to flush the write cache to disk. I think that any program that tries to write any files while the kernel is flushing the cache gets put into a wait state by the kernel until the cache flush is complete and then whatever write the program was attempting, gets written into the cache, ready to be flushed again on the next cache flush.
Furthermore, I theorize that for normal hard disk drives, the write speed is sufficient to keep "ahead" of cache flushes so that the cache never really "fills up" and no programs ever get waited in this way.
But that for slowish flash drives like mine, the kernel doesn't compensate for the slow write speed of the flash (because the kernel doesn't even realize that it's writing to flash?) and so it lets enough data buffer up that it has to frantically try to flush it all when the cache has filled up. Or perhaps, that the kernel just tries to flush too much at once, not realizing how slow the flush is going to be due to the underlying speed of the device.
I also theorize that this problem could be solved by having the kernel flush the cache more aggressively, and in smaller increments. If the flash drive were kept continually busy flushing small chunks of write cache, then a) the write cache would not be as likely to fill up, and b) no individual write would monopolize the device for such a long period of time becase the writes are all smaller.
Writing all of this makes me realize that the root cause may be that programs are trying to *read* from the device while a write cache flush is happening, and since the device can only do one operation (read or write) at a time, the long duration of the cache flush operation is blocking a program from reading the drive. Furthermore, if what the program is trying to read is a demand-paged part of its text segment, then it makes perfect sense that the whole process would be blocked by the kernel while the text segment piece waits to be loaded.
Am I even close to the mark on this one?
If so, I am sure there are Linux kernel experts who can tell me what values to write into what
Because SLC is both faster and more durable than MLC?
If J.K.R wrote Windows: Puteulanus fenestra mortalis!
db
I am literally 3000 tokens away from the chaotic crossbow --Stephen
Cowon A3, it supports more media formats than any MP3 player out (ogg, flak, mkv) there and you can read directly from a USB thumb drives. As a MP3 player the Cowon A3's audio quality blows the iPOD right out of the water, even has a 10 channel equaliser built in.
>I thought everyone knew that you get what you pay for, both speed and durability.
Sure, you get what you pay for. But the problem here is that these drives don't indicate on the packaging whether they use SLC or MLC memory, or whether they offer more than one channel.
So let's say the crappy variety of 4 GB USB drives currently go for $25, and the better, faster variety will never sell at that price. Right now, you have no way of knowing whether that 4 GB drive going for $50 is made with the faster, more durable SLC memory, or whether the drive is simply overpriced.
You can therefore spend $50 for a drive and not get what you paid for. And the only way to safeguard yourself is to waste time researching your drive -- something you shouldn't have to do, since this info ought to be published as part of the drive's specifications.
I'm generally "Interesting," "Insightful," and even "Funny" here. What the hell happens to me at parties?
I have always wondered why no one has mad a USB thumb drive with a flexible/swivel neck. Ive seen a few laptops with the USB sockets damaged after a user has connected the thumb drive then forgotten about it and then knocked it (thus cold soldering the laptops USB socket).
Well, that's easy. See, if you have a painfully slow drive, you use it less. So it'll last you for decades ;)
A polar bear is a cartesian bear after a coordinate transform.
Mod parent up! This is the heart of the problem right there: manufacturers don't write whether the USB drive (or SD card, or any other Flash RAM device) uses SLC or MLC Flash RAM. But that's the main difference. SLC Flash will survive 100.000 write/erase cycles, MLC only about 5000. That's a HUGE difference. Especially if you use the USB drive to host an OS that likes logging a lot. Each log write implies the whole Flash RAM block (usually 128 KB) to be erased and then written to.
Logging is the Flash RAM killer.
And Kingston and Sandisk should start putting "SLC" or "MLC" on their products, so we techies know whether they are worth the double price.
"The agriculture ministry is not in charge of Gundam" - Japanese ministry official.
When 8G flash drives suddenly dropped in price lately, I could choose between a Kingston and an I-Forget-The-Noname-Brand-Offhand at a local small retailer. I picked the Kingston. Installing Linux on it, something seemed terribly off. Reads were fast, but writes were deathly slow. I took it back and swapped with the noname brand, which was a bit smaller physically, and *much* faster in operation.
Love many, trust a few, do harm to none.
Latin languages doesn't have this problem, and there's no "free vs. free" ambiguity. Thus nobody speaking those languages has the impression that FSF is playing with words.
Besides, exFAT still costs money to the user, as Vista SP1's license explicitly requires that the user has bought a valid license for Vista, which almost never costs zero, except if the user got it through some channels as MSDNAA.
"Sufficiently advanced satire is indistinguishable from reality." - [Tips: 1DrYakQDKCQ6y52z6QbnkxHXAocMZJE61o ]
(And yes, I too have wandered down that sunny Day Dream avenue from time to time.)
You have to be about seven or eight years old, about six months after Star Wars came out and the best computer game available is "Pong" which takes up an entire counsel unit and is still pretty cool. Anyway, you have to show up one day at your friend's house or at school; some place where there's a handful of kids but no adults, and you have to have a modern laptop with you. You explain that it's a new Star Wars toy that they're testing but which hasn't "come out" yet, and that your Dad managed to bring one of the test units home from "the office". Nobody's sure if he really let you have it or if you're going to get in trouble when he finds out. Either way, that's incidental, because everybody is jostling to see what the heck it is you have on the table. It looks like it might have actually been IN a Star Wars film, that's for sure.
Then you crack open the lid and power it up, and muck around with the interface for a while. This should be sufficient to blow your audience away since things like GUI's and mouse pointers haven't been invented yet. --Flat screens which have better color and resolution than any TV set around are also new; just the sort of thing you'd expect a really expensive Star Wars toy to have. You might also want to pull the luminescent CD out of the Star Wars game package and put it in the extending CD tray. --Because Walkman-size consumer electronics have also not been invented, so just the size of the mechanics should also blow your friends away. Not to mention the Buck Rogers CD, (I still think the CD is a dead giveaway that we're all actually living in a low budget sci-fi movie of the week, but anyway. .
Then you start playing the Star Wars game. Music, sound effects, interface, it all looks better even than the best coin-op video game at the mall. A LOT better. You play this for about five or ten minutes, letting your friends have short tries before you suddenly have to go home because your Dad called and you need to bring the game back. And then it is never seen again. Until thirty years later, that is. --The stories which will circulate will not be taken seriously by parents, and yet a handful of kids will be jazzed beyond belief and will be scoping out Department Store Catalogs for the rest of their natural childhoods.
I had a friend who came back from Japan once with a fold-up robot toy which was lightyears ahead of anything our Western toy makers had ever produced. It was one of the coolest days of my entire life. I just picture that day times ten.
-FL
I was just discussing this the other day, and my friend found this: http://www.kingston.com/ukroot/flash/flashendurance.asp
Escher was the first MC and Giger invented the HR department.