Re: FreeBSD 5.3b7and poor ata performance

Am Samstag, 16. Oktober 2004 19:44 schrieb fandino:
[...]
> > Also, make sure that disk write-cache is enabled on both or disabled on
> > both.
>
> write-cache was enable on all tests and disks were in UDMA5 mode.
>
> In this new round of tests I add FreeBSD witch async and OpenBSD (always
> using the same hardware). FreeBSD is by far, the worst throughput of all
> (about 50% slower than others) :-?
>
> GNU/Linux 2.4.18 with ext2:               56848 K/sec
> FreeBSD 5.3b7 with default fs:            26347 K/sec
> FreeBSD 5.3b7 with default fs(async):     26566 K/sec
> FreeBSD 5.3b7 ata raid0* (two disks):     26131 K/sec
> FreeBSD 5.3b7 geom stripe* (two disks):   30063 K/sec
> FreeBSD 5.3b7 geom stripe** (four disks): 31891 K/sec
> OpenBSD 3.5 UFS fs:                       55277 K/sec
>
> * Each disk of the raid had a throughput of approx. 15000 K/sec
> ** Each disk of the raid had a throughput of approx. 7500 K/sec
> Each disk of the read split the throughput by half.
>
> How is possible that FreeBSD performs as bad?

I have to confirm that I also have even worse transfer rates.
It's a ICH2 (i815e) with a not so brand new 80GB WD, but I'd expext about 
50MB/s and I get 16MB/s.

One interesting thing is that the transferrate is constant with blocksizes 
from 256 Byte on. Only with a blocksize of 128 Bytes I can see reduced 
throughput (10MB/s).
I can remember, when I last did such "esoteric" tests throughput reached 
maximum at about 16k blocksize and rapidly degraded with blocksizes smaller 
than 10k. But now only very very small blocksizes limit the throughput!

Some excerpts: (i815 ich2, 5.3-RC1, custom kernel)

cale:/usr#22: atacontrol mode 0
Master = UDMA100
Slave  = BIOSPIO

ATA channel 0:
    Master:  ad0 <WDC WD800AB-00CBA0/03.06A03> ATA/ATAPI revision 5

atapci0: <Intel ICH2 UDMA100 controller> port 
0xffa0-0xffaf,0x376,0x170-0x177,0x3f6,0x1f0-0x1f7 at device 31.1 on pci0
ata0: channel #0 on atapci0
ata1: channel #1 on atapci0

cale:/usr#25: uname -a
FreeBSD cale.flintsbach.schmalzbauer.de 5.3-STABLE FreeBSD 5.3-STABLE #4: Sun 
Oct 17 02:33:58 CEST 2004     
root_at_cale.flintsbach.schmalzbauer.de:/usr/obj/usr/src/sys/CALE  i386