From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mirko Benz Subject: Re: SATA on mptsas performance Date: Wed, 01 Mar 2006 09:16:14 +0100 Message-ID: <4405584E.6070806@web.de> References: <43F2DDA7.7050700@web.de> <44051548.9090408@torque.net> <44053A8E.6000206@pobox.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from 162.237.ddkom.net ([212.80.237.162]:30381 "EHLO cheetah.dd.xiranet.com") by vger.kernel.org with ESMTP id S1751115AbWCAIQ5 (ORCPT ); Wed, 1 Mar 2006 03:16:57 -0500 In-Reply-To: <44053A8E.6000206@pobox.com> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Jeff Garzik Cc: dougg@torque.net, linux-scsi@vger.kernel.org Hello, As promised we have tested 3 Gb (aka SATA II) disks. Configuration: LSI SAS3442X controller, Promise SAS JBOD, 12 disks Seagate SATA 80 GB Tested with parallel dd invocations with bs=32k. The results look better: # disks Read AVG Write AVG 1 69 69,0 68 68,0 6 420 70,0 324 54,0 7 459 65,6 367 52,4 8 426 53,3 394 49,3 9 399 44,3 389 43,2 10 410 41,0 431 43,1 11 438 39,8 428 38,9 12 468 39,0 481 40,1 Available bandwidth is 4 * 3 Gb = 1.5 GB (4 lanes / external wide SAS port). So there is still some room for improvement. Has anyone else a similar setup and can provide results? Maybe with the Adaptec SAS controller? Thanks, Mirko Jeff Garzik schrieb: > Douglas Gilbert wrote: >> If the SATA disk does 3 Gb/sec then yes but SATA-1 disks >> run at 1.5 Gb/sec (and don't have NCQ). When a SAS HBA > > To further confuse things, "SATA-1", "SATA-2", etc. don't mean much at > all. I recommend never using these terms. > > There are many disks that can do NCQ but not 3 Gb/sec, for example. > > Its best just to mention the existence of features, because there is > no __technical__ definition of "SATA 2" that one can test in software. > SATA 2 is just a set of features defined by marketing. > > Jeff > >