From mboxrd@z Thu Jan 1 00:00:00 1970 To: 9fans@cse.psu.edu Subject: Re: [9fans] hardware acceleration From: nigel@9fs.org MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="upas-zgbklzlvsmofvgkyihgouuddlw" Message-Id: Date: Wed, 14 Feb 2001 07:44:15 +0000 Topicbox-Message-UUID: 6313731c-eac9-11e9-9e20-41e7f4b1d025 This is a multi-part message in MIME format. --upas-zgbklzlvsmofvgkyihgouuddlw Content-Disposition: inline Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit In support of this, it would seem that the access the vga chip affords to memory through the bus is inversely proportional to the speed at which it can bitblt itself. In other words, the more the chip does for you, the less the designers feel the need to put in decent bus access. What really ought to limit it is the priority access the playout has. So, it you want to speed up your vga i/o, perhaps turning down the refresh rate is the answer. Somehow I doubt it. --upas-zgbklzlvsmofvgkyihgouuddlw Content-Type: message/rfc822 Content-Disposition: inline Received: from mail.cse.psu.edu ([130.203.4.6]) by cpu; Wed Feb 14 00:52:26 GMT 2001 Received: from psuvax1.cse.psu.edu (psuvax1.cse.psu.edu [130.203.20.6]) by mail.cse.psu.edu (CSE Mail Server) with ESMTP id 040AE19A08; Tue, 13 Feb 2001 19:46:09 -0500 (EST) Received: from plan9.cs.bell-labs.com (ampl.com [204.178.31.2]) by mail.cse.psu.edu (CSE Mail Server) with SMTP id 48578199D5 for <9fans@cse.psu.edu>; Tue, 13 Feb 2001 19:45:07 -0500 (EST) From: "Russ Cox" To: 9fans@cse.psu.edu MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Message-Id: <20010214004507.48578199D5@mail.cse.psu.edu> Subject: [9fans] hardware acceleration Sender: 9fans-admin@cse.psu.edu Errors-To: 9fans-admin@cse.psu.edu X-BeenThere: 9fans@cse.psu.edu X-Mailman-Version: 2.0.1 Precedence: bulk Reply-To: 9fans@cse.psu.edu List-Id: Fans of the OS Plan 9 from Bell Labs <9fans.cse.psu.edu> List-Archive: Date: Tue, 13 Feb 2001 19:45:01 -0500 To address that, in 8bpp it's really not too much of an issue, but for higher modes the system is mostly unusable without scrolling and filling. It's not a question of the efficiency of the code (i.e., having a JIT wouldn't help). The problem is the readback speed on the VGA card, which nails you when you're doing software scrolling. I can read from my 5400rpm disk faster than I can read from my VGA memory. Russ --upas-zgbklzlvsmofvgkyihgouuddlw--