Date: Sat, 11 Sep 2004 12:49:23 +0200 From: =?ISO-8859-1?Q?S=F8ren_Schmidt?= <sos@DeepCore.dk> To: Frode Nordahl <frode@nordahl.net> Cc: current@freebsd.org Subject: Re: Promise PDC20267 ATA RAID, poor write performance Message-ID: <4142D833.4060802@DeepCore.dk> In-Reply-To: <EC95929E-031F-11D9-AA63-000A95A9A574@nordahl.net> References: <EC95929E-031F-11D9-AA63-000A95A9A574@nordahl.net>
next in thread | previous in thread | raw e-mail | index | archive | help
Frode Nordahl wrote: > Hello, >=20 > I have a intel S845WD1-E board with onboard Promise PDC20267 controller= =2E > The system is set up with a P4 2Ghz with 1GB RAM. > The board also has a Intel ICH2, but that's only used by a CDROM. >=20 > Disks connected: > ad4: 39205MB <Maxtor 6E040L0/NAR61590> [79656/16/63] at ata2-master UDM= A100 > ad6: 39205MB <Maxtor 6E040L0/NAR61590> [79656/16/63] at ata3-master UDM= A100 >=20 > I have them set up in a RAID1 >=20 > I have tried this on FreeBSD 4.10-RELEASE, and 6-CURRENT (from today)=20 > with similar results. >=20 > I also tried with RAID0, and that showed the same results*2, that is,=20 > ca. 7MB/s write instead of 3.5MB/s. >=20 > I have no previous experience with this hardware on other OS'es, so I'm= =20 > not sure what to expect, but I'm pretty sure it should be better than=20 > this :) >=20 > dmesg included below. >=20 > Doing simple tests show very poor write performance: > (reboot) > # dd if=3D/dev/zero of=3Dfill bs=3D1m count=3D2000 > 2000+0 records in > 2000+0 records out > 2097152000 bytes transferred in 588.383886 secs (3564258 bytes/sec) >=20 > (reboot) > # dd if=3Dfill of=3D/dev/null bs=3D1m > 2000+0 records in > 2000+0 records out > 2097152000 bytes transferred in 68.492015 secs (30618927 bytes/sec) OK I got this this setup now: atapci0: <Promise PDC20267 UDMA100 controller> port=20 0xb000-0xb03f,0xb400-0xb403,0xb800-0xb807,0xd000-0xd003,0xd400-0xd407=20 mem 0xfd000000-0xfd01ffff irq 16 at device 3.0 on pci0 ad1: 14305MB <Maxtor 2R015H1/EAH41MF0> [29065/16/63] at ata2-master UDMA1= 00 ad2: 14305MB <Maxtor 2R015H1/EAH41MF0> [29065/16/63] at ata3-master UDMA1= 00 ar0: 14305MB <ATA RAID1 array> [1823/255/63] status: READY subdisks: Controller the same, disks are an earlier verision of those "low=20 profile" Maxtor disks, just somewhat slover than yours. pizzabox# dd if=3D/dev/zero of=3Dfill bs=3D1m count=3D2000 2000+0 records in 2000+0 records out 2097152000 bytes transferred in 122.908771 secs (17062672 bytes/sec) pizzabox# dd if=3Dfill of=3D/dev/null bs=3D1m 2000+0 records in 2000+0 records out 2097152000 bytes transferred in 78.299524 secs (26783713 bytes/sec) Thats pretty much what I'd expect from this HW, so I risk saying that=20 ATA is working just as it should here. The only thing I could think of was if you have WC (write cache) turned=20 off for some reason which yields this result here: pizzabox# dd if=3D/dev/zero of=3Dfill bs=3D1m count=3D2000 2000+0 records in 2000+0 records out 2097152000 bytes transferred in 428.874993 secs (4889891 bytes/sec) That looks more like your results, but they are also within what I would = expect when not using WC.. -S=F8ren
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?4142D833.4060802>