From owner-freebsd-hardware Fri Aug 3 3:54:27 2001 Delivered-To: freebsd-hardware@freebsd.org Received: from mass.dis.org (mass.dis.org [216.240.45.41]) by hub.freebsd.org (Postfix) with ESMTP id 3781237B401; Fri, 3 Aug 2001 03:54:25 -0700 (PDT) (envelope-from msmith@mass.dis.org) Received: from mass.dis.org (localhost [127.0.0.1]) by mass.dis.org (8.11.4/8.11.3) with ESMTP id f73AuiB00834; Fri, 3 Aug 2001 03:56:44 -0700 (PDT) (envelope-from msmith@mass.dis.org) Message-Id: <200108031056.f73AuiB00834@mass.dis.org> X-Mailer: exmh version 2.1.1 10/15/1999 To: Joerg Micheel Cc: Mike Smith , "Jose M. Alcaide" , hardware@freebsd.org Subject: Re: 3ware Escalade 7xxx supported? In-reply-to: Your message of "Wed, 01 Aug 2001 09:08:29 +1200." <20010801090829.B17381@cs.waikato.ac.nz> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Fri, 03 Aug 2001 03:56:44 -0700 From: Mike Smith Sender: owner-freebsd-hardware@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.org > On Tue, Jul 31, 2001 at 12:55:43AM -0700, Mike Smith wrote: > > > I did a simple read performance test (dd if=/dev/twed0 of=/dev/null bs=64 > k) > > > and I got about 55 MB/s. Hey, that's good :-) > > > > Yes. 8) > > What do people do if they need 60, 90 or 120 MByte/sec throughput ? > I have done some experiments with SCSI and there appears to be a > cap around 80 MByte/sec, regardless how many disks or controllers > are involved (not a strict FreeBSD problem, only). Typically, you go wider and faster. A lot of controllers don't have the internal memory bandwidth to do more than about 80 or so; they are OK or even good at maximising the performance of their disks up to that point, but run out of puff beyond it. Intel recently released a new I/O chipset based on a very fast (733MHz) StrongArm core; it has two 64/66MHz PCI bridges and a decent memory interface. I'd guess that we'll see controllers using this appearing in a year or so, and based on the numbers I ran on this part a while back, they ought to be able to sustain something around 300MB/sec out of it. This is all vapour of course; I am only guessing that these parts will hit the mainstream RAID controller market. -- ... every activity meets with opposition, everyone who acts has his rivals and unfortunately opponents also. But not because people want to be opponents, rather because the tasks and relationships force people to take different points of view. [Dr. Fritz Todt] V I C T O R Y N O T V E N G E A N C E To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hardware" in the body of the message