Actually 16-20 sounds about right from what I have seen.

There is actually a lot of CPU work for USB (that's why intel pushes it)

In my informal testing, FireWire has faster transfers and lower CPU when
you use a decent FireWire card.

Don't be fooled by the 480 vs. 400 numbers, a lot of it's taken up by
overhead.





-----Original Message-----
From: tclug-list-bounces at mn-linux.org
[mailto:tclug-list-bounces at mn-linux.org] On Behalf Of Florin Iucha
Sent: Wednesday, September 29, 2004 3:04 PM
To: Leif Johnson; TCLUG Mailing List
Subject: Re: [TCLUG] USB hard drives

On Wed, Sep 29, 2004 at 01:38:08PM -0500, Leif Johnson wrote:
> I wouldn't expect the same latency or transfer rate from a USB drive
> as an IDE one.  I haven't actually done the math, but I don't think
> that the bus can support it.

USB 2.0 "480 MBs". I would expect a sustained throughput of 35-40 MB
or so, without much CPU usage. I get around 16-20 and the CPU is
working hard (it's a PII/450).

>                              Your latency and throughput will also
> depend on what other devices you have plugged into that controller,
> and the host/os implementation.

Nothing. Linux. 2.6.7.

> What filesystem is on the hard drive?

ext2

florin

-- 

Don't question authority: they don't know either!

_______________________________________________
TCLUG Mailing List - Minneapolis/St. Paul, Minnesota
Help beta test TCLUG's potential new home: http://plone.mn-linux.org
Got pictures for TCLUG? Beta test http://plone.mn-linux.org/gallery
tclug-list at mn-linux.org
https://mailman.real-time.com/mailman/listinfo/tclug-list