Very Slow deleting from USB thumb drive.

[audiorob]

Hello group - I've just transfered nearly 1 gig of files from my thumb
drive to my PC hard drive via USB 2.0 port and the transfer was
pleasingly fast. However, now I try to delete the files on the thumb
drive and the process is painfully slow deletes the files. What
gives? Why is it so slow deleting when the transferring (copying) was
so fast?? Watching task manager during the deleting process showed
very little use of CPU. I have a new 2.2 gig dual core processor.

Can anyone shed some light?

thanks,
Robert

 

[Arno Wagner]

Hello group - I've just transfered nearly 1 gig of files from my thumb
drive to my PC hard drive via USB 2.0 port and the transfer was
pleasingly fast. However, now I try to delete the files on the thumb
drive and the process is painfully slow deletes the files. What
gives? Why is it so slow deleting when the transferring (copying) was
so fast?? Watching task manager during the deleting process showed
very little use of CPU. I have a new 2.2 gig dual core processor.

Can anyone shed some light?

Writing to flash is inherently several orders of magnitude slower
than reading from it. Historically writing took something like
50ms and reading something like 1us, i.e. 50'000 times faster.
These times are over, but a speed difference by a factor of 10
is still not uncommon. Every write to FLASH damages it. The problem
is that writing FLASH fast, while possible, damages the FLASH more
than a slow write, so writes are slowed down, expecially in cheaper
FLASH (or, better: "not extremely expensive FLASH).

Arno

 

[mscotgrove]

Oops - I meant to give both the writing side and the deleting side of
the story, but I only gave the writing side.


How slow is "painfully slow"?  I found the write times to be
painfully slow, but, having figured out why they were so slow
I wasn't surprised at the long times needed for the deletes.
Basically, if your files only take a cluster or so on average
the delete will take about 1/2 the time as the copy.  If you have a
few MB or larger files in the mix the write time might not seem
so bad, but the delete time, taking 20 or more times the delete
time on a hard disk, might seem "painfully slow".













- Show quoted text -

You mention writing MFTs. This means that you are using NTFS.

I have not seen a 'customer' thumb drive that uses NTFS, all the ones
I see are FAT16 or FAT32.

Thumb drives do work OK as NTFS, but I expect it would need to be
converted first.

Is your thumb drive NTFS or FAT32?


Michael
www.cnwrecovery.com