From owner-freebsd-questions Wed May 1 15:58:26 1996 Return-Path: owner-questions Received: (from root@localhost) by freefall.freebsd.org (8.7.3/8.7.3) id PAA28624 for questions-outgoing; Wed, 1 May 1996 15:58:26 -0700 (PDT) Received: from kdat.calpoly.edu (kdat.csc.calpoly.edu [129.65.54.101]) by freefall.freebsd.org (8.7.3/8.7.3) with SMTP id PAA28619 for ; Wed, 1 May 1996 15:58:24 -0700 (PDT) Received: (from nlawson@localhost) by kdat.calpoly.edu (8.6.12/N8) id PAA12904; Wed, 1 May 1996 15:57:46 -0700 From: Nathan Lawson Message-Id: <199605012257.PAA12904@kdat.calpoly.edu> Subject: Re: Slowdown after RAM upgrade - 2.1.0R To: craigs@os.com (Craig Shrimpton) Date: Wed, 1 May 1996 15:57:46 -0700 (PDT) Cc: questions@freebsd.org In-Reply-To: from "Craig Shrimpton" at May 1, 96 03:42:29 pm X-Mailer: ELM [version 2.4 PL23] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-questions@freebsd.org X-Loop: FreeBSD.org Precedence: bulk > On Wed, 1 May 1996, Nathan Lawson wrote: > > >>I have noticed a real lag in disk activity after going from 16 megs to 32 megs >>I did recompile the kernel and added in the BOUNCE_BUFFERS option for DMA. >>I also changed MAXUSERS from 8 to 16. >> > > If by lag you mean less, that's what supposed to happen. More RAM means > less swapping which means less disk activity. If by lag you mean slower, > that's an entirely different problem. Yes, but what would I be complaining about if it swapped less? The problem is that I'll execute a command and it will hang for a second, then the disk light will flash, and the command will execute. When executed a second time, the command executes with normal speed. I interpret this as meaning that my ISA controller card is not running via DMA and thus is much slower (polled via interrupt). The second time, the program image is already in secondary memory and it executes quickly. Now, my question is, why? -- Nate Lawson "There are a thousand hacking at the branches of CPE Student evil to one who is striking at the root." CSL Admin -- Henry David Thoreau, 'Walden', 1854