From owner-freebsd-questions@FreeBSD.ORG Mon Nov 30 13:24:04 2009 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id B68E7106566C for ; Mon, 30 Nov 2009 13:24:04 +0000 (UTC) (envelope-from freebsd-questions@m.gmane.org) Received: from lo.gmane.org (lo.gmane.org [80.91.229.12]) by mx1.freebsd.org (Postfix) with ESMTP id 43A148FC19 for ; Mon, 30 Nov 2009 13:24:04 +0000 (UTC) Received: from list by lo.gmane.org with local (Exim 4.50) id 1NF6ET-0000bE-9f for freebsd-questions@freebsd.org; Mon, 30 Nov 2009 14:24:01 +0100 Received: from lara.cc.fer.hr ([161.53.72.113]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Mon, 30 Nov 2009 14:24:01 +0100 Received: from ivoras by lara.cc.fer.hr with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Mon, 30 Nov 2009 14:24:01 +0100 X-Injected-Via-Gmane: http://gmane.org/ To: freebsd-questions@freebsd.org From: Ivan Voras Date: Mon, 30 Nov 2009 14:23:44 +0100 Lines: 28 Message-ID: References: <4B13869D.1080907@zedat.fu-berlin.de> <0D3A9408-84A8-4C74-A318-F580B41FC1A6@exscape.org> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Complaints-To: usenet@ger.gmane.org X-Gmane-NNTP-Posting-Host: lara.cc.fer.hr User-Agent: Thunderbird 2.0.0.23 (X11/20090928) In-Reply-To: <0D3A9408-84A8-4C74-A318-F580B41FC1A6@exscape.org> Sender: news Cc: freebsd-stable@freebsd.org Subject: Re: Phoronix Benchmarks: Waht's wrong with FreeBSD 8.0? X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 30 Nov 2009 13:24:04 -0000 Thomas Backman wrote: > On Nov 30, 2009, at 9:47 AM, O. Hartmann wrote: > >> I'm just wondering what's wrong with FreeBSD 8.0/amd64 when I read the Benchmarks on Phoronix.org's website. Especially FreeBSD's threaded I/O shows in contrast to all claims that have been to be improoved the opposite. > Corrected link: http://www.phoronix.com/scan.php?page=article&item=freebsd8_benchmarks&num=1 > > And yeah, quite honestly: disk scheduling in FreeBSD appears to suck... The only reason I'm not switching from Linux. :( About the only useful result of the "Phoronix benchmark suite" in general is that benchmarking is hard, and that though tedious, statistical analisys and multiple runs actually have a realistic purpose. I suspect their runs have a very large variance between tests and are only useful in "order-of-magnitude" sort of comparisons. Most of their CPU-bound benchmarks therefore show results with insignificant differences, and most of the others benchmark the compilers. On the other hand, disk IO benchmarks like http://www.phoronix.com/scan.php?page=article&item=freebsd8_benchmarks&num=7 reflect the real state of the things, which can be easily demonstrated by a large number of other benchmarks (e.g. blogbench). AFAIK there is some speculation among developers about why is this so, but nothing definite yet. For what it's worth, ZFS effectively does a fair bit of its own IO scheduling, so persons interested in this particular aspect should also try the tests with ZFS. My own tests (with other benchmarks) show that ZFS helps significantly, though the cumulative result is still significantly worse than Linux's.