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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?
Probably at first the copy was just being buffered into memory. Linux buffers copies and then flushes the buffered data to disk later, when the drive is otherwise idle, to improve overall system performance. Once you filled the cache, you had to wait to write more data into it until some of it was flushed to make room. And thus, once the cache is filled, any more writes happen at the actual speed of the device, instead of the speed to copy to memory.
That's one theory. There may be other reasons.
In terms of how these results compare to other products, I think they are "pretty good". Not the best, but significantly better than average.
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.
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
If J.K.R wrote Windows: Puteulanus fenestra mortalis!
>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?
It can't be an objection to its freeness (as in beer) or you wouldn't use linux.
It can't be an objection to its restrictiveness, or you wouldn't be using (or attempting to use) Windows.
And it can't be that the shareware license prevents that specific use of the software, because doesn't the Windows EULA stipulate against running Windows from virtual machines, mobile devices or while enjoying ice cream? Ok, just kidding about the virtual machine, I believe that restriction came about with Vista.
db
I am literally 3000 tokens away from the chaotic crossbow --Stephen
Get a short piece of cable and duck tape it to the thumb drive.
I'll never make that mistake again, reading the experts' opinions. - Feynman
the inconsistencies are inherant in most flash drives. that particular flash drive is not as bad as others but it still happens. writing a file takes more time writing the begining and end bits of hte file, once that is written, the data can be transfered at it's top speed. if you transfer many small files at once to a flash drive, it will take significantly longer to transfer then transfering a single large file of the same overall size.
.pst files, it the speeds were stellar, when it then started to transfer alot of sub 1MB files, it slowed down. but even then, i walked away for less then 5 minutes, and when i came back, a 1.5 GB profile was transfered to a new pc, when it took 20 minutes plus to do the same size profile with a regular flash drive
with that in mind, i've had to transfer multiple profiles as part of an install for a customer, most were 2+ gigabites. I also just purchased that same exact flash drive. When transfering their
Do you have objective numbers to back up that claim, like perhaps some RMAA tests? Or are you acting no better than the subjectivist audiophools who spend thousands on power cables?
I dub thee... Sir Phobos, Knight of Mars, Beater of Ass.
Oh, I'm sure the poster has numbers and isn't a jerk that comes up for reasons to hate things because they are popular~
The Kruger Dunning explains most post on