Re: GURU needed: Linux vs. FreeBSD

Lenart Gabor (lgb@hal2000.hal.vein.hu)
Fri, 6 Nov 1998 11:27:11 +0100


On Fri, Nov 06, 1998 at 12:18:04AM +0100, Peter Mutsaers wrote:
> FreeBSD was faster in all cases, sometimes a bit, sometimes a lot.
>
> For example, my new UDMA disk got 12MB/s with 2% CPU on FreeBSD, on
> Linux I got 7MB/s with more (about 15%) CPU usage.

Did you try to speed up your drive with hdparm ? My QUANTUM Fireball
5.1EL gives about 7MB/s, but after some hdparm commands I got
11Mb/s ! It's possible that Linux does not support UDMA _BY_DEFAULT_
and you must to turn on it manually. Using DMA would reduce CPU
usage (UDMA instead of CPU controlled PIO) so it would reduce the
CPU usage as well, IMHO.

Interesting that after some hours it usually fall back to 3Mb/s (!!).
I'm using 2.0.36pre15 with a Soyo mainboard, so - as far as I know -
it's IDE PCI chipset is not directly supported. I haven't tried a 2.1.x
kernel with my new computer yet, though ...

---[ LGB/DC ]------------------[ root@hal2000 ]-----------------[ LINUX ]---
"The truth is out there" "We're living together" "The future is dark."
---[ 88/422022-4602 ]--[ http://www.hal.vein.hu/~lgb ]------[ 87/477074 ]---

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