Months back I was looking on eBay for a cheap thumbdrive. I noticed something odd. A lot of no-name Chinese vendors were selling higher capacity thumb drives than American vendors I'd done business with before (Sandisk and PNY). And these drives were cheap, too! So, I bought a couple 4GB drives and they worked fine. I was one happy camper.
That was until I replaced the hard disk in my basement computer and that entailed reinstalling a bunch of software, including that of my RadioShark. I don't use my basement computer much. It basically sits down there and waits until Sunday morning whereupon it wakes up and runs a Tivo-like program on my RadioShark that records Jazz Brunch on my local classic rock station, WLAV. About a month went by and I had a lot of recorded stuff downstairs piling up. (Jazz Brunch runs when I'm in church and I figure it's a fair use to time-shift it for listening during the week. Disagree? Sue me.)
After a while, I copied the recordings to a thumb drive and took it upstairs to my laptop to listen to. Didn't work. I was distracted and I let more time pass. I figured the problem was some stupid DRM on the Windows WMA recording format. I switched to WAV. It seemed to work at the expense of massive files. After working once, that failed, too. A week later, I switched to MP3s. Still no workie.
Hmmmmm. I really am not dumb, though I act that way occasionally. I finally got bothered enough by what was obviously something that should be working not working that I payed attention to what I was doing. And I couldn't find my no-name high capacity thumb drive, so I picked up a 1GB drive from PNY. It took all the files and carried them to my laptop safely.
This is what they say in the detective business is called a clue.
(Oddly, I had already done an XCOPY/v and it said everything was fine. Liar.)
Then I formatted the cheapo 4GB drive and carried files to my laptop just fine. I copied more files and this time I tested each file after copying it. After a dozen or so files, everything I copied afterwards would be corrupted. Strangely, even if I deleted some files, subsequent files would be corrupt. So, I reformatted the 4GB drive and copied a bunch of MP3s thereto. I looked at each file to see where the file corruption started.
Turned out that the first bunch of files were OK, but the next one was bad half-way through and all files copied thereafter were bad. I deleted just the bad and half-bad files and then checked the properties of the good files. They summed to 933MB and the half-bad file had been over 100mb.
OK, the drive lets me format and thereafter copy up to 1GB of files thereto correctly. After that WinXP, and even DOS's XCOPY, say that all is fine while copying data into corrupt data. Just writing to that 2nd GB and beyond causes the thumbdrive to thereafter store corrupt data without warning. Not good.
Is this a cautionary tale? Not to buy el cheapo thumb drives off eBay from insidious Hong Kong merchants, but to stick with known vendors like PNY or SanDisk?
Idunno. I'm going to repeat this experiment with a different cheapo drive. And I'm CERTAINLY going to be more thorough about testing thumbdrives in the future.
Update: I performed these experiments on the 2nd el-cheapo thumb drive and also on a 4GB SanDisk Cruzer drive as described here