How fast is your pendrive?

Forum: Other Help Topics
Topic: How fast is your pendrive?
started by: humpty

Posted by humpty on Dec. 23 2005,15:01

Gee I went out an bought the fastest pendrive I could lay me hands on, but it doesn't feel the DSL drivers can push it to it's limits. And so I google a couple of articles, this is just one of them: < http://www.everythingusb.com/usb2/faq.htm >

Basically it seems USB 1.1 runs at either 1.5mbit/s or 12mbit/s and USB 2.0 can be low-speed, full-speed (12mbits/s) or HiSpeed (480mbit/s).

Currently I run a PQI USB pendrive spec'd at 25/17mbyte/s (read/write) which can top 22/15 mbytes/s in windoze but in DSL it varies. I kept getting different timings so I used a shell to check on the size, instead of emelfm (which just falls asleep).

It appears for writing, there's a 128Mbyte cache which fills in 15secs, but actual writing (when all the lights go out and emelfm is released) is slow: 750kbytes/s (6mbits/s). read is about the same speed (but doesn't seem to use the cache). And it doesn't seem to care what brand or speed the pen/flash drive is, as I used a Sandisk+card-reader combo to compare (supposed to be a lot slower) but get the same results.

So here I am scratching my head why there's such a big difference compared with windoze (750kbytes vs 15mbytes /sec) - this is not good. It means I can no longer boast to my friends about DSL anymore. I can only guess the linux drivers do not fully support "hispeed' USB2.0?

So I'm asking how fast is your pendrive? and I do pray it's lot faster than mine.

Posted by doobit on Dec. 23 2005,15:35

Good job measuring the timing! I haven't checked mine, but, I also can't figure out how to run WindowsXP from a pendrive!?

Posted by pr0f3550r on Dec. 23 2005,16:16

You haven't specified how you have formatted your pendrive, how you are running
DSL and how it is mounted on the filesystem. However usb drives are slow in read/write but fast in execution.

Posted by roberts on Dec. 23 2005,18:32

This is old news. Please read the change logs. There was a typo bug causing booting from USB 2.0 to not work and only USB 1.1. It has since been fixed with the v2.1RC1.

Posted by humpty on Dec. 23 2005,19:51

]pr0f3550r
It's a fat16 holding the backup.tar.gz and mydsl's.

> It has since been fixed with the v2.1RC1.
That's good news. I will try new iso. thanks.

Posted by humpty on Dec. 23 2005,23:42

Okay, 2.1Rc2 works.
write: 7.8 mbytes/s ! read : 5.2 mbytes/s (surprisingly).
not optimum, but good enough for me.