From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Lord Subject: Re: SAS v SATA interface performance Date: Sat, 01 Dec 2007 22:49:00 -0500 Message-ID: <47522B2C.2010205@rtr.ca> References: <47506237.3000406@clear.net.nz> <47507F9A.3080109@msgid.tls.msk.ru> <20071130231705.51e056f4@the-village.bc.nu> <475110A8.5090709@clear.net.nz> <87f94c370712010637o5efa9c4rd9a86ec5a3cba6ff@mail.gmail.com> <4751B3DA.6030508@clear.net.nz> <4751BDA4.9080102@rtr.ca> <4751C6DA.3080409@garzik.org> <4751F482.60204@clear.net.nz> <47522A45.50706@rtr.ca> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from rtr.ca ([76.10.145.34]:2698 "EHLO mail.rtr.ca" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753849AbXLBDtB (ORCPT ); Sat, 1 Dec 2007 22:49:01 -0500 In-Reply-To: <47522A45.50706@rtr.ca> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Richard Scobie Cc: Jeff Garzik , linux-ide@vger.kernel.org Oh, more fiction: > Because SATA uses point-to-point connectivity, the scaling > available with SAS controllers is not possible with SATA > controllers. SATA drives must be connected on a one-to-one > basis with the SATA connectors on the controller =96 i.e, a fourport > SATA controller can connect up to four drives, an eight-port > SATA controller can connect up to eight drives, etc. This means > that the number of drives needed must be known prior to > purchasing a SATA controller, or additional hardware costs will > be incurred. Ignoring port multipliers (hubs) again there. A SATA hub can connect up to 31 drives to a single SATA port, or up to 248 drives per 8-port PCI(X/e) controller card. I don't know if anyone currently sells a 31-port multiplier, though. Cheers