Subject: Re: [ehci] USB-2.0 transfer rate
To: Petar Bogdanovic <p+netbsd@2005.smokva.net>
From: Tamas Eichkern <wow@inf.elte.hu>
List: netbsd-users
Date: 06/26/2005 08:40:24
On Sun, 26 Jun 2005 03:44:40 +0200, Petar Bogdanovic wrote
> Hi,
> 
> Tamas Eichkern wrote:
>  >>
>  >>The results are ok, but they don't come close to the promised 480Mb/s
>  >>resp. 60MB/s:
>  >>
>  > AFAIK these values are normal. Think about it, your memory stick 
> and harddrive > is the bottleneck here.
> 
> Definitely. I've tested my laptop-hd today and found out, that it 
> reads/writes at the same speed.
> 
> And that's not surprising at all, because they are both 2.5 inch 
> IDE-drives with 5400rpm.
> 
>  > For example, my fastest harddrive is capable of ~ 25
>  > MiB/s, while communicating using UDMA 133, which enables 133 MiB/s
>  > transfer rate, theoretically.
> 
> What do you mean with 'MiB'? MegaByte or MegaBit?
MiB means mebibyte. For more information read
http://en.wikipedia.org/wiki/Mebibyte. :)
>  > I really want to see a harddrive capable of 480 MiB/s :)
> 
> Take any modern IDE UDMA133-disc with 7200rpm. They read at least 
> with ~480Mb/s aka 60MB/s.
Hmmm. I thought 480 MiB, not Mibits... My fault. Anyway, it's a fact my drives
are slow (even when UDMA turned on). :)
> Petar

Tamas Eichkern