From owner-freebsd-hackers Thu Aug 9 16:10:37 2001 Delivered-To: freebsd-hackers@freebsd.org Received: from yonge.cs.toronto.edu (yonge.cs.toronto.edu [128.100.1.8]) by hub.freebsd.org (Postfix) with SMTP id 318B837B401; Thu, 9 Aug 2001 16:10:33 -0700 (PDT) (envelope-from khui@cs.toronto.edu) Received: from jane.cs.toronto.edu ([128.100.2.31]) by yonge.cs.toronto.edu with SMTP id <33963-21682>; Thu, 9 Aug 2001 19:10:28 -0400 Received: from gardiner.cs.toronto.edu by jane.cs.toronto.edu id <453140-21860>; Thu, 9 Aug 2001 19:10:18 -0400 Date: Thu, 9 Aug 2001 19:10:06 -0400 From: Kevin Hui X-Sender: khui@gardiner.cs To: freebsd-questions@freebsd.org, freebsd-hackers@freebsd.org Subject: Experiencing very slow raw write speeds on /dev/ad1 Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG Hi all, I have installed 2 Maxtor UDMA100 drives in my system, sharing the channel ide0. /dev/ad0 contains all the FreeBSD partitions and ad1 is used as a scratch drive (there's nothing on it). Ide1 channel is used for the DVD drive (which doesn't support UDMA): ad0: 39083MB [79408/16/63] at ata0-master UDMA100 ad1: 39083MB [79408/16/63] at ata0-slave UDMA100 acd0: DVD-ROM at ata1-master using PIO4 Running rawio (available from the Ports collection under benchmarks) on /dev/ad1 shows the following: # rawio -p 1 -r /dev/ad1 Random read Sequential read Random write Sequential write ID K/sec /sec K/sec /sec K/sec /sec K/sec /sec ad1 36175.1 2208 # rawio -p 1 -w /dev/ad1 Random read Sequential read Random write Sequential write ID K/sec /sec K/sec /sec K/sec /sec K/sec /sec ad1 950.1 58 The single-process sequential read time is very good (~36MB/s) but the single-process sequential write time is terrible (950.1KB/s). Does anyone have any idea why this is happening? How complete is the support for UDMA under FreeBSD? I'm using the VIA 82C686 onboard ATA100 controller. Any information would be appreciated. -Kevin. ----------------------- FreeBSD 4.3-RELEASE #0: Sat Apr 21 10:54:49 GMT 2001 jkh@narf.osd.bsdi.com:/usr/src/sys/compile/GENERIC Timecounter "i8254" frequency 1193182 Hz CPU: Pentium III/Pentium III Xeon/Celeron (1004.52-MHz 686-class CPU) Origin = "GenuineIntel" Id = 0x686 Stepping = 6 Features=0x383f9ff real memory = 268353536 (262064K bytes) avail memory = 256905216 (250884K bytes) ... atapci0: port 0xb800-0xb80f at device 4.1 on pci0 ata0: at 0x1f0 irq 14 on atapci0 ata1: at 0x170 irq 15 on atapci0 To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message