[clug] OT - USB flash timings
Robert Edwards
bob at cs.anu.edu.au
Mon Jun 18 00:05:47 GMT 2007
Hi Steve,
Can you tell us what your actual testing methodology was? Were you using
dd to a raw device, or something else to copy to a filesystem - which
one (assuming DOS/VFAT, but can you confirm)?
Cheers,
Bob Edwards.
steve jenkin wrote:
> I got a question from a cousin about his new USB flash taking an age to
> copy something...
> Thought the group might be interested...
>
> Seems standard devices are very sensitive to block size on *write* - but
> not on read...
>
> For some good reference material: Wikipedia and Kingston:-
>
> <http://www.kingston.com/products/pdf_files/FlashMemGuide.pdf>
> <http://en.wikipedia.org/wiki/Flash_Memory>
>
>
> Device used for these tests: 4Gb Kingston 'Data Traveller'.
> 512Mb file used for most timings (1Mb for 1b test). No FileSystem Cache
> issues.
>
>> USB Flash - WRITE performance
>> 1b 88,827 bytes/sec
>> 8k 1,035,601 bytes/sec
>> 128k 3,819,827 bytes/sec
>> 512k 4,155,635 bytes/sec
>>
>> USB Flash - READ performance
>> 8k 9,467,708 bytes/sec
>> 16k 9,448,265 bytes/sec
>> 32k 9,386,199 bytes/sec
>> 64k 9,475,763 bytes/sec
>> 128k 9,466,469 bytes/sec
>> 256k 9,453,077 bytes/sec
>> 512k 9,415,421 bytes/sec
>> 1024k 9,482,868 bytes/sec
> Hope this is interesting/helpful.
>
> regards
> stevej
>
More information about the linux
mailing list