From owner-freebsd-hackers Mon May 20 14:24:04 1996 Return-Path: owner-hackers Received: (from root@localhost) by freefall.freebsd.org (8.7.3/8.7.3) id OAA18413 for hackers-outgoing; Mon, 20 May 1996 14:24:04 -0700 (PDT) Received: from phaeton.artisoft.com (phaeton.Artisoft.COM [198.17.250.211]) by freefall.freebsd.org (8.7.3/8.7.3) with SMTP id OAA18362 for ; Mon, 20 May 1996 14:23:58 -0700 (PDT) Received: (from terry@localhost) by phaeton.artisoft.com (8.6.11/8.6.9) id OAA28500; Mon, 20 May 1996 14:19:17 -0700 From: Terry Lambert Message-Id: <199605202119.OAA28500@phaeton.artisoft.com> Subject: Re: ISDN Compression Load on CPU To: michaelh@cet.co.jp (Michael Hancock) Date: Mon, 20 May 1996 14:19:17 -0700 (MST) Cc: bsdi-users@bsdi.com, freebsd-hackers@freebsd.com In-Reply-To: from "Michael Hancock" at May 21, 96 00:38:55 am X-Mailer: ELM [version 2.4 PL24] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-hackers@FreeBSD.ORG X-Loop: FreeBSD.org Precedence: bulk > SDLComm has a new PCI card called the RISCom/Pri. Primary rate has 23 > 64Kbps B-Channels. I wonder how many cards can be put into a P90 box > running BSD Unix before the compression overloads the CPU? The RISC CPU you mean.. dunno. > How heavy is the computational load of something like STAC compression? As a percentage of CPU: depends on your CPU. As a percentage of file I/O overhead: ~17%, assuming average cache locality, degrading to ~36% for cache-busting (like IOZone). This was on a 486 DX/2-66, so your mileage may vary. Terry Lambert terry@lambert.org --- Any opinions in this posting are my own and not those of my present or previous employers.