From owner-freebsd-questions@FreeBSD.ORG Thu Feb 26 04:16:50 2009 Return-Path: Delivered-To: questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id D1D341065678 for ; Thu, 26 Feb 2009 04:16:50 +0000 (UTC) (envelope-from josh@tcbug.org) Received: from out1.smtp.messagingengine.com (out1.smtp.messagingengine.com [66.111.4.25]) by mx1.freebsd.org (Postfix) with ESMTP id AA21A8FC2A for ; Thu, 26 Feb 2009 04:16:50 +0000 (UTC) (envelope-from josh@tcbug.org) Received: from compute1.internal (compute1.internal [10.202.2.41]) by out1.messagingengine.com (Postfix) with ESMTP id 8B3982A3B4B for ; Wed, 25 Feb 2009 22:58:05 -0500 (EST) Received: from heartbeat2.messagingengine.com ([10.202.2.161]) by compute1.internal (MEProxy); Wed, 25 Feb 2009 22:58:05 -0500 X-Sasl-enc: 5fXSxaCoxFGKBARjW799soGP+ABkchLi8LzIhS0lOVvA 1235620685 Received: from [10.0.1.198] (c-66-41-132-62.hsd1.mn.comcast.net [66.41.132.62]) by mail.messagingengine.com (Postfix) with ESMTPSA id 3A807310C2 for ; Wed, 25 Feb 2009 22:58:05 -0500 (EST) Message-Id: From: Josh Paetzel To: questions@freebsd.org Content-Type: text/plain; charset=US-ASCII; format=flowed; delsp=yes Content-Transfer-Encoding: 7bit Mime-Version: 1.0 (Apple Message framework v930.3) Date: Wed, 25 Feb 2009 21:58:04 -0600 X-Mailer: Apple Mail (2.930.3) Cc: Subject: SAS drives seem slow X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 26 Feb 2009 04:16:51 -0000 I have a 3ware 9690SA SAS RAID controller in a PCI-e 8x slot with Fujitsu MBA series 15k SAS drives attached, and the array is coming up as: da0 at twa0 bus 0 target 0 lun 0 da0: Fixed Direct Access SCSI-5 device da0: 100.000MB/s transfers da0: 138272MB (283181056 512 byte sectors: 255H 63S/T 17627C) The controller is probed as: twa0: <3ware 9000 series Storage Controller> port 0x2000-0x20ff mem 0xe0000000-0xe1ffffff,0xe4100000-0xe4100fff irq 16 at device 0.0 on pci2 twa0: [ITHREAD] twa0: INFO: (0x15: 0x1300): Controller details:: Model 9690SA-4I, 128 ports, Firmware FH9X 4.06.00.004, BIOS BE9X 4.05.00.015 FreeBSD services.tcbug.org 8.0-CURRENT FreeBSD 8.0-CURRENT #0: Mon Feb 16 21:07:14 UTC 2009 root@:/usr/obj/usr/src/sys/SERVICES amd64 But 6.x and 7.x give similar results. The disks themselves are capable of sequential read/write in the 180 Meg/sec range, so I'm trying to understand why I'm being told they are 100 Meg/sec, and why that seems to be their real world performance cap. # dd if=/dev/zero of=stuff bs=8m count=100 100+0 records in 100+0 records out 838860800 bytes transferred in 8.711125 secs (96297644 bytes/sec) Thanks, Josh Paetzel