USB flash drive question.

[Cy Yunga]

I have a 1GB flash drive, does that mean its supposed to hold 1000MB or 1024 MB? either way, the amount of space it really holds is much less than its claimed capacity - something like 970MB. where does all that space go? I'm thinking it could be the U3 programs on it, but on my other 1GB USB there is no U3 whatsoever and it only holds 953MB. So... what happened to all that storage space?

 

[AltF4]

Giga, Mega, Kilo and the rest are prefixes for a base 10 number system. Computers of course work in a Binary system, not in ten. We use those terms simply because we're used to them and can easily identify with how large it is. But the actual amounts are slightly different.

So, it is the second one. A Gig actually hold 1024 MB. But also keep in mid that a Megabyte is actually 1024 KB, and so on...

Also, depending on what kind of device it is that you're using, there might be preloaded data such as drivers and stuff that you can't erase which are on your stick. (Though a flash stick shouldn't need drivers...) It could also be fragmentation that reduces your storage capacity though. But nobody ever defrags a flash stick .

 

[Cy Yunga]

Oh. Okay.
2 more random questions: What does defragmenting do? And how do I use CruzerSync which comes with my U3 stuff?

 

[AltF4]

Well, I don't know much about Cruzer specifically, but I can answer your first question!

Imagine your hard drive like the computer sees it, not as a round disk, but rather a straight line of locations it can save stuff to. The computer numbers these locations from zero all the way up to however large your drive is.

Keep in mind that this isn't EXACTLY how a modern operating system actually does stuff, but it gives you the idea.

Say you save a file on your drive that takes up some space, then later you save something else. That second file you saved gets put right after the first one, so on the disk, the files are right next to each other. This process can continue so that your disk gets filled up, with no empty space "between" files.

But now suppose you delete a file. There is now a "hole" where the file used to be. The next time you save a file, the operating system will try to fill that hole if it big enough. But what are the chances that the new file is exactly the right size to perfectly fill the hole? Not very good. Realistically what happens is that you wind up with a small "sliver" of unused memory that is too small to fit anything in. It may not be very big, but this principle can continue until your disk has a lot of "free" space, but not all together. It's scattered and unusable. The small unusable area between files is referred to as "external fragmentation".

So defragmenting is the process of picking up all of your files, and lining them back up again so that there are no spaces between.

 

[Cy Yunga]

Oh. Thanks.

Defragmenting doesn't affect any of your files, does it?

 

[AltF4]

Not unless something goes wrong during it! But don't worry about it, defrag tools do a bunch of nifty stuff to keep all of your files safe.

 

[pdk]

that 30mb loss is probably caused by inevitable overhead from the file system (usb drives use ancient-*** FAT12 by default, which isn't good about being efficient but is chosen since it works with every modern OS), not much you can do about that really

 

[Cy Yunga]

I see... sandisk lies about its flash drives capacity

what happens if you try to defragment the songs you have on an ipod?