Date: Thu, 22 Oct 1998 12:04:50 +0200 (MET DST) From: Nick Hibma <nick.hibma@jrc.it> To: Luigi Rizzo <luigi@labinfo.iet.unipi.it> Cc: sos@FreeBSD.ORG, hackers@FreeBSD.ORG Subject: Re: multi-user: multiple consoles in FreeBSD Message-ID: <Pine.GSO.3.95q.981022120028.17573L-100000@elect8> In-Reply-To: <199810220803.JAA11764@labinfo.iet.unipi.it>
next in thread | previous in thread | raw e-mail | index | archive | help
> Speaking of USB: i have read that bus throughput with a single node is > reported at about 750KB/s, whereas with multiple nodes bus throughput > falls down very rapidly (because of arbitration etc ?) to 250KB or so. > So i would not want a HD on it! At max of 1mb/s a second (I can't remember the exact theoretical maximum, but it should be more than 750Kb/s) you dont' want to have more than a floppy attached to that port. Except if you have a portable like my colleague. It's so slim it only has one PCMCIA slot. And that one is used for ethernet. A hub is small enough to take with you and a hard disk is easily connected. Nah, I think you are wrong in some cases. But the figures come probably from a winDOS installation. Call M$ $upport and they will tell you that you then will have to move the HD onto the root hub and you will be allright. But with nothing talking, even with a number of hubs in between the HD and the root hub you should be able to get maximum performance. Bus arbitration is done completely by the root hub, so you should be able to dedicate the whole link to one device. Even interrupt traffic is scheduled by the root hub and _not_ the device. Nick -- building: 27A address: STA-ISIS, T.P.270, Joint Research Centre, 21020 Ispra, Italy tel.: +39 332 78 9549 fax.: +39 332 78 9185 To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?Pine.GSO.3.95q.981022120028.17573L-100000>