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 1LdTwn-0001r2-TP for garchives@archives.gentoo.org; Sat, 28 Feb 2009 18:30:02 +0000 Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id CDA96E015B; Sat, 28 Feb 2009 18:30:00 +0000 (UTC) Received: from wf-out-1314.google.com (wf-out-1314.google.com [209.85.200.169]) by pigeon.gentoo.org (Postfix) with ESMTP id 94794E015B for ; Sat, 28 Feb 2009 18:30:00 +0000 (UTC) Received: by wf-out-1314.google.com with SMTP id 29so1834277wff.10 for ; Sat, 28 Feb 2009 10:30:00 -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=2EGThu7JDYsXj8D5KrQwDjwFSBdA9UKgAHqov+kw1o0=; b=HvalYFAL/fUzyD9VXd5y+OiCF4TF5VRQKiMOFYH8m4YmKr1jRC8GJmYO83JNCQnP/K gW0yi5JQ5MUODxEFkZgjVSpCqdr/JktsDzBCHITHsHKe5qDc1TAND3Cawv/YIzKiqWWE I1L5z8stj5MeHjDZRHp2AS3VEMf4cj1GwaY9c= 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=lRlfsq3npzqBlS/rz65lvSj6yz5CNTtmlLmeGEzCdPElTgwtMduNxZ9ee6x3n/GI+9 Ap6JA3+sQ/FiePGLWRECndKwPir3CoDVxxgGpNviTmha++BlEU8iF7/mV0+nj6m2J5Q6 UOHZmQWh8npAcGYtU+Iw5X27s+DIW9s+VgjIQ= 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 10.142.207.8 with SMTP id e8mr1979076wfg.278.1235845800204; Sat, 28 Feb 2009 10:30:00 -0800 (PST) In-Reply-To: <49bf44f10902280654y4dd8da38mfadbb63d43067bf9@mail.gmail.com> References: <49bf44f10902261934l1d33ff17nd64fbfaff4d5b1a3@mail.gmail.com> <49A78BA0.8030602@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> Date: Sat, 28 Feb 2009 10:30:00 -0800 Message-ID: <5bdc1c8b0902281030g27c18dc3v9ecd20bc49c7b844@mail.gmail.com> Subject: Re: [gentoo-user] Re: Which USB device on which controller? From: Mark Knecht To: gentoo-user@lists.gentoo.org Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-Archives-Salt: 4eeeecdd-77ac-4954-8c33-6caff7e70447 X-Archives-Hash: e40bf3313912ecef87089f4b5bf972f6 On Sat, Feb 28, 2009 at 6:54 AM, Grant wrote: >>>>> 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? =C2=A0I don't need 2.0 speeds between each webc= am >>> 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. =C2=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. =C2=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. 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. =C2=A0It >> doesn't matter what the controller is capable of -- it matters >> what speed it's actually talking. >> >> -- >> Grant > >