EDU Me on Flash Drives

Discussion in 'OT Technology' started by freshie, Feb 21, 2007.

  1. freshie

    freshie New Member

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    Hey guys,

    Ok so i picked up this headunit for my car, its a Kenwood KDC-MP532U, one of the biggest reasons i got it is it has a USB hookup wire for either flash drives or an ipod.

    I purchased a 2gb flash drive from Micro Center for $10, it was a "Micro Center" brand one. It seems to be doing the trick, but i've been noticing when i go to select some songs that they are almost sounding corrupted. Like today i hit random and it popped up a Jet song, but it was halfway through the song where it started.

    Now could it be the flash drive i bought just sucks for mp3's or is there something else wrong? I checked the song on my home pc and it plays fine, just for some reason playing off this flash drive it cuts into the song. Is it possible for a file to "degrade" or just crap out on a flash drive? As is i found 2gb is not enough music, so im looking for another one. But if this is how these flash drives are maybe i'll just save up for a ipod
     
  2. crontab

    crontab (uid = 0)

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    what is the speed of the flash drive?

    Also have you deleted some music, put some back, deleted again, put some more back, etc...

    I've noticed on some flash devices, usb, compact, sd, even mp3 players etc. that fragmentation kills streaming performance, i.e. playing music, videos.

    When I normally need to change a large amount of data on the flash drives, I just wipe it all out and copy my data back onto it again.
     
  3. freshie

    freshie New Member

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    not exactly sure of the flash drives speed.

    when i first copied music on it and noticed shit was fucking up(one of my albums sounded like the chipmunks) i hooked it back up to my pc and saw it was fat format. I reformatted it to fat32 and copied my stuff back over. I haven't noticed anything missing yet, but i've only listened to like half of what i put on it.

    i was debating on lunch just going home and copying the folder(i made a special folder so i dont have to repick songs out in case anything screws up like it is now) and seeing if that fixes it, but if its just its a shitty flash drive, i may just cough up some cash and get a new one
     
  4. deusexaethera

    deusexaethera OT Supporter

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    Fragmentation can affect performance of any storage medium just because it takes extra time to chase down all the fragments, but on flash memory the performance degradation is MUCH smaller because every single byte is accessible all at once (because it's all hardwired), whereas on a disk each fragment will have to be physically located and read.

    If your head unit isn't playing the songs correctly, it could be that the file format on the flash drive is wrong (apparently some head units demand FAT16 instead of FAT32), or it could be that the mp3 decoder in your head unit is cheap/fucked up.
     
  5. freshie

    freshie New Member

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    I dont think its the headunit itself, i've had no other problems with it playing mp3s that were burned to a cd. Just on this flash drive. So is there any types of flash drives that are good?

    i just cant figure out how its causing the songs to fuckup. :( Nothing more annoying than a good song starting and its halfway in or fucks up

    Looking on crutchfields site, on one review i saw this

    Does this mean FAT only or FAT 32?

    and this

    maybe my files bit-rate being off is causing it to "hiccup" files?



    http://www.kenwood.com/usb/compatibility/k.html
     
    Last edited: Feb 21, 2007
  6. deusexaethera

    deusexaethera OT Supporter

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    It's possible that your head unit uses an implementation of FAT that reads FAT32 incorrectly instead of just not reading it at all (possibly due to a software glitch), but that seems unlikely. Nevertheless, since your flash drive is 2GB, it's small enough to format in FAT16, which is readable by any computer made in the past...oh...30 years or so.

    The bit-rate issue sounds like the most likely problem. If you're using variable bit-rates, that requires extra processing that could bog down the wimpy little decoder inside your head unit. Separate out some of your mp3s according to their bitrates, put them in separate folders on the flash drive, and see if you can establish a pattern of bitrates that work vs. ones that don't.
     
  7. freshie

    freshie New Member

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    will do, already been keeping a little list of what songs screw up to check against on my pc. at first i thought maybe it was a virus or something screwed up with my pc, since currently i keep getting a message that a system fan has stopped/restarted non stop on my pc at home, had to turn off intel active monitoring because of it. I wasn't sure if maybe in transferring the files to the flash drive if the pc froze for a second and thats why the song came over corrupted. I'll try this out and see what happens and post up.

    one question though, what is the difference between fat & fat32 and your files. Like if my pc is fat32, and a drive is just fat (lol this sounds funny) does it have any effect on files?
     
  8. crontab

    crontab (uid = 0)

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    please shut the fuck up. you are so fucking annoying.
     
  9. MrBrotato

    MrBrotato New Member

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    :ugh:

    He's right.
     
  10. deusexaethera

    deusexaethera OT Supporter

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    Your PC's hard drive almost certainly uses NTFS, a Windows-specific file system that is much more protected against data corruption than the older FAT32 and FAT16 file systems. That really doesn't affect whether your computer can read FAT file systems though; see, if you ignore advanced features like encryption and journaling and whatnot, the only difference between file systems is the way the table of contents is encoded -- if you know the code, you can read the table of contents, and like I said before, any computer you're likely to see in your life will know how to read FAT16 and FAT32 disks.
     
  11. crontab

    crontab (uid = 0)

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    Explain to me the concept of "hardwired" pertaining to flash memory and how fragmentation of data doesn't affect these so-called hardwired devices as "MUCH".

    -tony72
     
  12. deusexaethera

    deusexaethera OT Supporter

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    Because, to retrieve data from memory, all you have to do is request data from address x and it will be queried and delivered by the memory controller -- whereas to retrieve data from a disk, the OS may still only have to request data from address x, but the disk will have to line up its moving parts before it can read the data.

    With a lightly-fragmented filesystem the difference will be negligible because hard drives have higher throughput compared to flash memory, and that will make up for the longer seek time once data starts streaming, but with a heavily-fragmented filesystem, the difference between a few thousand (or million) data accesses that take 10ns apiece as opposed to 10ms apiece will become apparent in short order.

    And yes, I'm assuming that each storage medium is being used by a single-user system, because that's the situation that the OP is almost certainly in.
     
  13. crontab

    crontab (uid = 0)

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    Wow. Here we go yet again. Where's hardwiring come into play? You sure do know how to talk, without any knowledge on the subject I may add, but sure can talk. Like a lawyer. Like your father. Take some generic assumptions and basic logic from a wiki or a class and make it sound fancy.

    If I spewed this crap at SNIA, I be the laughing stock of the world and be out of a job.

    Anyway, tony72 > you.
     
  14. deusexaethera

    deusexaethera OT Supporter

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    Hardwiring comes into play because it reduces the seek time for each disk access to virtually nothing -- on a flash drive, there are no spinning platters and no readers that have to be aligned before data can be read, all of the medium is accessible at the exact same time, so the only penalty for reading fragmented files is the extra time it takes to request data from multiple blocks on the medium instead of one contiguous block.

    How does it really perform then, if not the way I say it does? Since you know better, that is. :jerkit:
     
  15. crontab

    crontab (uid = 0)

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    Awesome, thanks. The more you know.

    I don't know, I just listen to you since you like to talk so much.

    Again, tony72 > you.
     

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