Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Wed, 24 Oct 2001 08:24:27 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Wed, 24 Oct 2001 08:24:07 -0400 Received: from home.geizhals.at ([213.229.14.34]:62726 "HELO home.geizhals.at") by vger.kernel.org with SMTP id ; Wed, 24 Oct 2001 08:23:59 -0400 Message-ID: <3BD6B278.3070300@geizhals.at> Date: Wed, 24 Oct 2001 14:22:16 +0200 From: Marinos Yannikos User-Agent: Mozilla/5.0 (Windows; U; Win98; en-US; rv:0.9.5) Gecko/20011011 X-Accept-Language: de-AT,en,el MIME-Version: 1.0 To: linux-kernel@vger.kernel.org Subject: gdth / SCSI read performance issues (2.2.19 and 2.4.10) Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hi, our brand-new ICP GDT8523RZ controller with 6 disks peaks out at 45MB/s under 2.4.10, while with 2.2.19 it reaches 85MB/s (seq. read performance). It should realistically be able to reach at least 150-200MB/s in this configuration (RAID-5, 6 disks, it's a 64-bit 66MHz PCI card). It's in a dual P3-1GHz box with Tyan 2510NG board. Sequential write performance is OK with both kernels, it's higher than the read performance on 2.4.10 (60MB/s). Under 2.4.10, when I test the performance with a simple program that just read()'s 16MB blocks from /dev/sda, both CPUs report 40-50% System time usage. 2.2.19 reports ~20% for one CPU (and better performance). Is there anything that can be done about this? It seems like a serious performance problem either with the gdth driver or the kernel and it renders this neat controller rather ineffective. Regards, -mjy [please CC: answers] - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/