Re: Crappy hdparm performance on new machine

[Mike Dresser <mdresser_l@windsormachine.com>]

On Fri, 9 Apr 2004, Roberto Sanchez wrote:

> it has been great.  Extremeley quiet (I chose a 600 MHz fanless Eden CPU

Ding.

Cyrix Cpu, and like all cyrix's, low in performance(which is the whole
point of this cpu being low power)  Memory bus is likely slow to go with
it.

> # hdparm -tT /dev/hda
>
> /dev/hda:
>   Timing buffer-cache reads:   128 MB in  1.85 seconds = 69.19 MB/sec
>   Timing buffered disk reads:  64 MB in  1.53 seconds = 41.83 MB/sec
> Hmm.. suspicious results: probably not enough free memory for a proper test.

The following two systems are 3ware 7000-2 cards with 2 120 gig drives in
a raid1.

Here's a P4 2.6C with 2x256 pc3200 dimms, dual channel.

 Timing buffer-cache reads:   128 MB in  0.24 seconds =533.33 MB/sec
 Timing buffered disk reads:  64 MB in  1.55 seconds = 41.29 MB/sec

Here's a Celeron 1.7ghz with 2x256 pc3200 dimms at pc1600 speed, single
channel.

 Timing buffer-cache reads:   128 MB in  0.36 seconds =355.56 MB/sec
 Timing buffered disk reads:  64 MB in  1.19 seconds = 53.78 MB/sec

And my home workstation is a old Celeron 600, not a clue on memory, just
that it's a mix that gives 224 meg total.  Pc66 speed for sure.  Dual 160
in software raid.

 Timing buffer-cache reads:   128 MB in  1.22 seconds =104.92 MB/sec
 Timing buffered disk reads:  64 MB in  1.18 seconds = 54.24 MB/sec

So you can see it's largely your motherboard/cpu combo that determines the
first number, and your disks can vary.  I should probably open up that
2.6C and see why the hdparm values vary so much (not that hdparm is a
reliable benchmark anyways)

Mike