From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from pigeon.gentoo.org ([69.77.167.62] helo=lists.gentoo.org) by finch.gentoo.org with esmtp (Exim 4.60) (envelope-from ) id 1LdrLj-00077p-7N for garchives@archives.gentoo.org; Sun, 01 Mar 2009 19:29:19 +0000 Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id EAE2CE036A; Sun, 1 Mar 2009 19:29:16 +0000 (UTC) Received: from rv-out-0708.google.com (rv-out-0708.google.com [209.85.198.244]) by pigeon.gentoo.org (Postfix) with ESMTP id AB3A2E036A for ; Sun, 1 Mar 2009 19:29:16 +0000 (UTC) Received: by rv-out-0708.google.com with SMTP id f25so1924607rvb.46 for ; Sun, 01 Mar 2009 11:29:16 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:in-reply-to:references :date:message-id:subject:from:to:content-type :content-transfer-encoding; bh=nzSO+lMQq43PG8VGnmsnVvNM2Hqw6Vx1gz98hkdOUSI=; b=fXiMAj5j6bDZ4ZME/pmhQa4FyVxQRn9Wl6oL0fZmqyUSG8ga4KIJLJg/tamLaG2wiZ DNyymrta2cM8ZA87a3djjLD/dRWw5obFgqsuZbMbU1JvwIYDItjrDVBbUpQVH/JG+94N l4axPEJUWhkL3/dsOCvtIEiM5feRcUM2SHOUQ= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type:content-transfer-encoding; b=qvXng6VT2aDJh0/5BQeOlb8nxLe8bGJrK66QEj2fD+vsTdrid7TgfKoIjF/sc3SLtk TgmvIgissjpXBw96Va5L6MU00Z5lHqT5TbmrFuDWg7FGUiH3E7AgcqWySLb/ci8fj5xz HVLdxhRRdBKucoJCuY11zLTyt+AT8v2hlBYwQ= Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-Id: Gentoo Linux mail X-BeenThere: gentoo-user@lists.gentoo.org Reply-to: gentoo-user@lists.gentoo.org MIME-Version: 1.0 Received: by 10.115.94.1 with SMTP id w1mr2275912wal.30.1235935756057; Sun, 01 Mar 2009 11:29:16 -0800 (PST) In-Reply-To: <5bdc1c8b0902281030g27c18dc3v9ecd20bc49c7b844@mail.gmail.com> References: <49bf44f10902261934l1d33ff17nd64fbfaff4d5b1a3@mail.gmail.com> <49bf44f10902270737s7cd41da0t734fdc00d5c67a73@mail.gmail.com> <49A80CEE.5000200@gmail.com> <49bf44f10902270900q2ec748f6p489fc1839bf32f7d@mail.gmail.com> <49A82351.8090009@gmail.com> <49bf44f10902271221k30134a9fg907bc477dfc3683@mail.gmail.com> <49bf44f10902280654y4dd8da38mfadbb63d43067bf9@mail.gmail.com> <5bdc1c8b0902281030g27c18dc3v9ecd20bc49c7b844@mail.gmail.com> Date: Sun, 1 Mar 2009 11:29:15 -0800 Message-ID: <49bf44f10903011129w56e74398m5c29b32544d26b63@mail.gmail.com> Subject: Re: [gentoo-user] Re: Which USB device on which controller? From: Grant To: gentoo-user@lists.gentoo.org Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable X-Archives-Salt: 8d9e9354-2588-4eb5-aeba-f70885a2239d X-Archives-Hash: ea6ba3cbaaa89ee946b33b040caa34c4 >>>>>> Sounds like it's a 1.1 device to me. >>>>> >>>>> Yep, that's what it sounds like to me too. >>>>> >>>>> Dale >>>> >>>> But that's OK isn't it? =A0I don't need 2.0 speeds between each webcam >>>> and the controller, I just need the increased overall bandwidth of a >>>> 2.0 controller so one of the 1.1 webcams doesn't use all of it. >>> >>> The 2.0 controller doesn't _have_ increased bandwith if it's >>> talking to 1.1 devices. =A0In that case, the 2.0 controller is >>> transferring data at the same speed as a 1.1 controller. >> >> I thought the total bandwidth available for a controller was different >> than the bandwidth at which it communicates with one device. =A0You're >> saying any 1.1 device that uses 12 mbit/s will 100% monopolize a 2.0 >> controller so no other devices can function? >> > > Yes. USB is not like 1394/Firewire. Firewire will increase and > decrease bandwidth as different devices take control of the bus. There > is negotiation between devices and the device that owns the bus > controls how the bus is used. > > With USB a 1.1 device on the bus causes the 2.0 controller to operate > at 1.1 speed so there is only 12Mb/S on that bus once you plug the 1.1 > web cam in. > >> Taking a different approach, since I have 2 USB controllers (EHCIx1, >> OHCIx1) why can't I operate one webcam on one controller and one >> webcam on the other controller so they can both function? >> > > If the hardware is working correctly, if the drivers are independent, > and IF IF IF the two physical ports you chose are actually going to > completely different controllers then you can. I do this. This sort of > thing becomes an issue with USB when you make a mistake an plug an old > USB mouse or keyboard into the wrong physical port and bring your 2.0 > bus speed down to 1.1 bandwidth. That's a lot of IFs. This USB PCI card looks good because it claims: "Five ports in three independent host controller design, two OHCI and one E= HCI" http://www.newegg.com/Product/Product.aspx?Item=3DN82E16815104202 Are you saying I can't count on this card behaving as 3 separate USB controllers? - Grant > Over and out, > Mark > >> - Grant >> >>>> I get the feeling I have a misconception somewhere along the >>>> line here. Could someone straighten me out? >>> >>> A Corvette going 3MPH will get to the finish line at exactly >>> the same time as a 4-year-old kid on a tricycle going 3MPH. =A0It >>> doesn't matter what the controller is capable of -- it matters >>> what speed it's actually talking. >>> >>> -- >>> Grant