From owner-freebsd-hackers Fri Feb 23 14:30:23 2001 Delivered-To: freebsd-hackers@freebsd.org Received: from perec.uol.com.br (perec.uol.com.br [200.231.206.204]) by hub.freebsd.org (Postfix) with ESMTP id C1C9A37B491 for ; Fri, 23 Feb 2001 14:30:17 -0800 (PST) (envelope-from obelix@lcmi.ufsc.br) Received: from jazz.lcmi.ufsc.br (200-191-104-159-as.acessonet.com.br [200.191.104.159]) by perec.uol.com.br (8.9.1/8.9.1) with ESMTP id TAA21711; Fri, 23 Feb 2001 19:30:49 -0300 (BRT) Received: (from obelix@localhost) by jazz.lcmi.ufsc.br (8.9.3/8.9.3) id TAA01351; Fri, 23 Feb 2001 19:25:01 -0300 Date: Fri, 23 Feb 2001 19:25:01 -0300 From: Rafael Rodrigues Obelheiro To: Peter Pentchev Cc: Torbjorn Kristoffersen , "Michael C . Wu" , FreeBSD-Hackers Subject: Re: IOmega ZIP problem Message-ID: <20010223192501.G199@lcmi.ufsc.br> References: <20010222131933.C20955@peorth.iteration.net> <20010223093943.A1899@ringworld.oblivion.bg> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Mailer: Mutt 1.0.1i In-Reply-To: <20010223093943.A1899@ringworld.oblivion.bg>; from roam@orbitel.bg on Fri, Feb 23, 2001 at 09:39:43AM +0200 X-PGP-Key: http://www.lcmi.ufsc.br/~obelix/obelix.asc Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Fri, Feb 23, 2001 at 09:39:43AM +0200, Peter Pentchev wrote: > On Thu, Feb 22, 2001 at 01:19:33PM -0600, Michael C . Wu wrote: > > On Thu, Feb 22, 2001 at 07:40:16PM +0100, Torbjorn Kristoffersen scribbled: > > | Hi I'm using 4.2-RELEASE, with a parallel port ZIP drive (100M). > > | Whenever I copy a large file from the zip drive (for example /dev/da0s1), > > | the "cp" process eats 98% of the system resources. What's behind all this? > > | Is there a way to fix it? > > | > > | 711 root 54 0 280K 168K RUN 0:45 93.87% 93.21% cp > > | > > | A 'renice' won't help. > > > > > > That's natural with "parallel". No way around it. > > To clarify a bit, parallel port hardware depends on the system processor > doing all the data transfers, every single byte, and spending even more > time checking if it's time for the next byte to go. There's no DMA, there's > not even a controller you can tell 'here's a 512-byte block, let it fly'. > > There's no way around it indeed. AFAIK, ZIP drives support parallel ports in EPP mode (uncertain about ECP), which is much faster than conventional (either nibble or bidirectional) modes. According to imm(4), FreeBSD supports EPP mode for ZIP drives. You might want to check if you can enable EPP in your BIOS. Regards, -- Rafael Rodrigues Obelheiro obelix@lcmi.ufsc.br Florianopolis, SC, Brasil To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message