From owner-freebsd-hardware@FreeBSD.ORG Mon Oct 16 12:05:04 2006 Return-Path: X-Original-To: freebsd-hardware@FreeBSD.ORG Delivered-To: freebsd-hardware@FreeBSD.ORG Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 8750E16A4D4 for ; Mon, 16 Oct 2006 12:05:04 +0000 (UTC) (envelope-from olli@lurza.secnetix.de) Received: from lurza.secnetix.de (lurza.secnetix.de [83.120.8.8]) by mx1.FreeBSD.org (Postfix) with ESMTP id 5E90B43D90 for ; Mon, 16 Oct 2006 12:01:38 +0000 (GMT) (envelope-from olli@lurza.secnetix.de) Received: from lurza.secnetix.de (jylqnu@localhost [127.0.0.1]) by lurza.secnetix.de (8.13.4/8.13.4) with ESMTP id k9GC1BHJ003197; Mon, 16 Oct 2006 14:01:16 +0200 (CEST) (envelope-from oliver.fromme@secnetix.de) Received: (from olli@localhost) by lurza.secnetix.de (8.13.4/8.13.1/Submit) id k9GC17ol003191; Mon, 16 Oct 2006 14:01:07 +0200 (CEST) (envelope-from olli) Date: Mon, 16 Oct 2006 14:01:07 +0200 (CEST) Message-Id: <200610161201.k9GC17ol003191@lurza.secnetix.de> From: Oliver Fromme To: freebsd-hardware@FreeBSD.ORG, soralx@cydem.org In-Reply-To: <200610150041.59870.soralx@cydem.org> X-Newsgroups: list.freebsd-hardware User-Agent: tin/1.8.2-20060425 ("Shillay") (UNIX) (FreeBSD/4.11-STABLE (i386)) X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-2.1.2 (lurza.secnetix.de [127.0.0.1]); Mon, 16 Oct 2006 14:01:20 +0200 (CEST) Cc: Subject: Re: Quiet computer X-BeenThere: freebsd-hardware@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: freebsd-hardware@FreeBSD.ORG, soralx@cydem.org List-Id: General discussion of FreeBSD hardware List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 16 Oct 2006 12:05:04 -0000 soralx@cydem.org wrote: > > neither do I care how fast it is on someone else's system :p, but I'm > just curious whether the speed VIA claims, 25Gbps(!) peak is achievable Note that that number is just the "raw" rate at which the circuit can produce bits. You still have some processing overhead in the kernel and in the userland application that uses the random device. There's no "zero-copy random device" yet. ;-) I also think that 25 Gbit/s is overly optimistic. I guess it can only achieved for a short period ("burst"), hence they call it peak. It's certainly not designed to keep that data rate for a longer sustained period. > > I just care that it offloads the ALU. I haven't gotten around to > > proving whether (and by how much) it does so. > > did you get to the point that you're sure it's being used? Now that's easy. Just type "sysctl kern.random". If you get a bunch of lines talking about "yarrow" and "harvest", then the kernel's software PRNG is used. If you get an error message "unknown oid 'kern.random'", then a hardware generator is being used. Best regards Oliver ("VIA C3 Nehemiah+RNG+AES ") -- Oliver Fromme, secnetix GmbH & Co. KG, Marktplatz 29, 85567 Grafing Dienstleistungen mit Schwerpunkt FreeBSD: http://www.secnetix.de/bsd Any opinions expressed in this message may be personal to the author and may not necessarily reflect the opinions of secnetix in any way. "Unix gives you just enough rope to hang yourself -- and then a couple of more feet, just to be sure." -- Eric Allman