Re: hard drive

Date sent:      	Mon, 21 Oct 2002 07:28:19 +0200
From:           	Mark Santcroos <[email protected]>
To:             	Randy Bush <[email protected]>
Copies to:      	FreeBSD Laptoppers <freebsd-
[email protected]>
Subject:        	Re: hard drive

> On Sun, Oct 20, 2002 at 12:26:25PM -0700, Randy Bush wrote:
> > for me, the bottleneck on laptops is the disk throughput.  the hard
> > drives themselves are slow, and the bandwidth to them sucks.  for
> > big makes etc., a 10GHz cpu would not improve throughput as much as
> > doubling the disk goodput.
> > 
> > is anybody making laptoys with real disk i/o subsystems?
> 
> Imho the gap between desktop and laptop is getting smaller. There are
> quite some laptops shipping with UDMA100 now.
> 
> "dd if=/dev/ad0 of=/dev/null bs=4096" gives me 22 MB/s. I don't have a
> recent desktop so I don't know how this compares to recent desktop
> performance but I don't think it is bad.

As some general info:

I just did the same (count=10000) on a 'recent desktop' AMD1333 with 
ATA100 / 7200rpm Maxtor 740-DX drives, ad0 (40GB) giving me 
22MB/s, ad4 (80GB) at 34MB/s.

Laptop Celeron 500 / IBM HD : 16 MB/s

More important in the laptop-arena is the difference in available HD's. 
With two laptops and two HD's I measured the time for "ls -lR /usr/ports" 
(and yes, both directories were identical ;-) ):

Celeron  500 / IBM DJSA-220 : 1m56s
Celeron 1100 / IBM DJSA-220 : 1m37s
Celeron  500 / toshiba MK2018 : 6m21s
Celeron 1100 / toshiba MK2018 : 5m35s

(ls -lR /usr/ports on my desktop -> 0m40s)

The toshiba was standard with the 1100-laptop (low-budget, from 2 
months ago so I should expect that sort of performance), the IBM was a 
replacement drive (for the 500) bought separately about a year ago.

So it looks to be more a difference of access time than of basic 
throughput. Anyway, just a few numbers, nothing scientific,

Harry

To Unsubscribe: send mail to [email protected]
with "unsubscribe freebsd-mobile" in the body of the message