From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Garzik Subject: Linux: Why software RAID? Date: Wed, 23 Aug 2006 23:34:25 -0400 Message-ID: <44ED1E41.40606@garzik.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Sender: linux-raid-owner@vger.kernel.org To: Linux Kernel , Linux RAID Mailing List , marc@perkel.com List-Id: linux-raid.ids Mark Perkel wrote: > Running Linux on an AMD AM2 nVidia chip ser that supports Raid 0 > striping on the motherboard. Just wondering if hardware raid (SATA2) is > going to be faster that software raid and why? First, it sounds like you are confusing motherboard "RAID" with real RAID. There's a FAQ for this sort of thing: http://linux-ata.org/faq-sata-raid.html In particular, your motherboard's Raid 0 striping (a) is not done in hardware, and (b) has nothing to do with SATA2. But anyway, to help answer the question of hardware vs. software RAID, I wrote up a page: http://linux.yyz.us/why-software-raid.html Generally, you want software RAID unless your PCI bus (or more rarely, your CPU) is getting saturated. With RAID-0, there is no duplication of data, and so, PCI bus and CPU usage should be about the same for hardware and software RAID. Jeff