From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from deck1210.hostdeck.com ([212.39.12.10]) by canuck.infradead.org with esmtps (Exim 4.63 #1 (Red Hat Linux)) id 1GxQvZ-0005o4-In for linux-mtd@lists.infradead.org; Thu, 21 Dec 2006 11:37:54 -0500 Message-ID: <458AB6B3.40500@fatti.com> Date: Thu, 21 Dec 2006 17:30:43 +0100 From: Enrico Migliore MIME-Version: 1.0 To: Indrek Kruusa Subject: Re: Transfer rates with NAND References: <458A73AF.2040307@artecdesign.ee> In-Reply-To: <458A73AF.2040307@artecdesign.ee> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: linux-mtd@lists.infradead.org List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Indrek Kruusa wrote: > Hi, > > I am wondering which NAND transfer rates are seen in embedded Linux > projects. What to expect from the whole hardware/software subsystem? > I have one Geode LX design with CS5536 companion chip which by using > built-in 8-bit Flash controller on PCI bus gives me slightly over 2MB/s. > It's almost the same with Linux MTD driver and with a self-made basic > driver. Is the speed here the matter of flash controller only? Which is > the fastest flash controller out there? :) > > thanks in advance, > Indrek > > Hi Indrek, the data transfer from the NAND to the CPU and viceversa depends on: 1. NAND bus maximum speed 2. CPU's bus controller speed (*) and its configuration 3. Read or Write operarations The overhead added by the MTD layer or any other well written driver is irrelevant. (*) I mean the bus that access the NAND which might not be the same bus that access the RAM Enrico