Re: HD performance question
Daniel Pittman <daniel@rimspace.net> writes:
> On Mon, 18 Nov 2002, Olaf Meeuwissen wrote:
> > I'm a minimalist and rolled my own kernel. It was absolutely bare
> > bones and that had a noticable effect on hard disk performance. So I
> > tinkered around a bit with kernel options and tested performance with
> > hdparm -tT. Now I'd like to know what all those numbers mean and if
> > they are reasonable (for my Dynabook SS S4/275PNHW).
> >
> > I've repeated all tests five times and dropped outliers. With my
> > initial kernel I get
> >
> > ~110 MB/sec for buffer-cache reads
> > ~ 2 MB/sec for buffered disk reads
> >
> > After tinkering I get
> >
> > ~ 55 MB/sec for buffer-cache reads
> > ~ 14 MB/sec for buffered disk reads
> >
> > Question 1: Which of the two is "better" and why?
>
> The second, because 2MB/second is PIO, while the second is DMA
> transfers. So, buffer-cache reads may be slower... but not using 100%
> CPU when you touch the hard disk is worth it. :)
>
> > Question 2: Can I do better than this?
>
> No.
Because?
> > I still think hard disk performance is a bit slow but that may be just
> > me.
>
> It is. You have a laptop, which means a 5400RPM drive is *fast*. Don't
> expect desktop performance out of these poor little drives. :)
I don't.
> One of the best ways to improve laptop performance is more memory
> because, always, the hard drive performance is not going to be great.
Maxed that one out already.
--
Olaf Meeuwissen EPSON KOWA Corporation, ECS
GnuPG key: 6BE37D90/AB6B 0D1F 99E7 1BF5 EB97 976A 16C7 F27D 6BE3 7D90
LPIC-2 -- I hack, therefore I am -- BOFH
Reply to: