[gentoo-user] Does USB devices share bandwidth?
Hello. My old sparc server have a USB extension card, which provides two USB slots at the back of the machine, driving a USB printer on Slot A. This printer runs at heavy load. because it cannot print the documents as fast as we need, I wish to add another printer. In most casese, we need the two printer working together the same time rather then one after the other. The two USB slots provided by the USB card are both OHCI (some USB 1.x stuff, not USB 2.0). So far it seems one single printer uses up all the USB bandwidth (sometimes printer stop there several seconds wait for signal). What would happen if I put another Printer there? case A: the new printer uses the bandwidth on slot B, both run as fast as if they were the only USB printer; case B: the new printer share bandwidth with the old one, the result is both printer work 1/2 fast, that is equal to not having bought another printer at all. Which one is true? Thanks in advance:) -- gentoo-user@gentoo.org mailing list
Re: [gentoo-user] Does USB devices share bandwidth?
case A: the new printer uses the bandwidth on slot B, both run as fast as if they were the only USB printer; case B: the new printer share bandwidth with the old one, the result is both printer work 1/2 fast, that is equal to not having bought another printer at all. Which one is true? None, and both. Printer can not print as fast as you can pump data through usb2 (480Mbps), unless you have some *really* expensive printer. So even if you had 2 printers on usb, sharing common usb-bandwidth, you could print much more documents in the same time, as with 1 printer... Jarry -- gentoo-user@gentoo.org mailing list
Re: [gentoo-user] Does USB devices share bandwidth?
On 6/22/06, 张�|武 [EMAIL PROTECTED] wrote: Hello. My old sparc server have a USB extension card, which provides twoUSB slots at the back of the machine, driving a USB printer on Slot A.This printer runs at heavy load. because it cannot print the documents as fast as we need, I wish to add another printer. In most casese, weneed the two printer working together the same time rather then oneafter the other.The two USB slots provided by the USB card are both OHCI (some USB 1.xstuff, not USB 2.0). So far it seems one single printer uses up all theUSB bandwidth (sometimes printer stop there several seconds wait forsignal). What would happen if I put another Printer there?case A: the new printer uses the bandwidth on slot B, both run as fast as if they were the only USB printer;case B: the new printer share bandwidth with the old one, the result isboth printer work 1/2 fast, that is equal to not having bought anotherprinter at all.Which one is true? Thanks in advance:)--gentoo-user@gentoo.org mailing listAccording to http://www.sounddevices.com/tech/usbbasics.htm if the ports are on the same controller, they share bandwith. It probably depends on the hardware if it provides controller for each port or not. I think mostly it's two ports per controller, but dunno how to determine it... From lspci, and lsusb I would think that in my case (nforce4ultra) it's only one controller, but to share 10 ports ? Nonsense. In windows it shows 5 devices, which would correspond with the idea of 2 ports per controller... but dunno how to see that in linux. You could probably plug some usb flash storage in and perform transfers to see if it slows down the printing, to be sure :)Caster
Re: [gentoo-user] Does USB devices share bandwidth?
Hi,If there are only two ports on the card, there is almost certainly a single hub controller on the card, so they would share the available bandwidth. That would be a max of 12Mbits/second for 1.1.On 6/22/06, Caster [EMAIL PROTECTED] wrote: On 6/22/06, 张�|武 [EMAIL PROTECTED] wrote: Hello. My old sparc server have a USB extension card, which provides twoUSB slots at the back of the machine, driving a USB printer on Slot A.This printer runs at heavy load. because it cannot print the documents as fast as we need, I wish to add another printer. In most casese, weneed the two printer working together the same time rather then oneafter the other.The two USB slots provided by the USB card are both OHCI (some USB 1.xstuff, not USB 2.0). So far it seems one single printer uses up all theUSB bandwidth (sometimes printer stop there several seconds wait forsignal). What would happen if I put another Printer there? case A: the new printer uses the bandwidth on slot B, both run as fast as if they were the only USB printer;case B: the new printer share bandwidth with the old one, the result isboth printer work 1/2 fast, that is equal to not having bought anotherprinter at all.Which one is true? Thanks in advance:)--gentoo-user@gentoo.org mailing list According to http://www.sounddevices.com/tech/usbbasics.htm if the ports are on the same controller, they share bandwith. It probably depends on the hardware if it provides controller for each port or not. I think mostly it's two ports per controller, but dunno how to determine it... From lspci, and lsusb I would think that in my case (nforce4ultra) it's only one controller, but to share 10 ports ? Nonsense. In windows it shows 5 devices, which would correspond with the idea of 2 ports per controller... but dunno how to see that in linux. You could probably plug some usb flash storage in and perform transfers to see if it slows down the printing, to be sure :)Caster -- sternklang[EMAIL PROTECTED]
Re: [gentoo-user] Does USB devices share bandwidth?
On 6/22/06, 张�|武 [EMAIL PROTECTED] wrote: The two USB slots provided by the USB card are both OHCI (some USB 1.x stuff, not USB 2.0). So far it seems one single printer uses up all the USB bandwidth (sometimes printer stop there several seconds wait for signal). Are you *sure* this is due to USB bandwidth? Many printers have to do internal processing of the document before they start printing, and depending upon the complexity of the document, I've seen printers take several seconds to several minutes to print each page. Simple text documents are usually fast, but complex graphics can take a long time. You might be better off upgrading to a single workgroup-class network-enabled printer. -Richard -- gentoo-user@gentoo.org mailing list
Re: [gentoo-user] Does USB devices share bandwidth?
Richard Fish wrote: On 6/22/06, 张�|武 [EMAIL PROTECTED] wrote: The two USB slots provided by the USB card are both OHCI (some USB 1.x stuff, not USB 2.0). So far it seems one single printer uses up all the USB bandwidth (sometimes printer stop there several seconds wait for signal). Are you *sure* this is due to USB bandwidth? Many printers have to do internal processing of the document before they start printing, and depending upon the complexity of the document, I've seen printers take several seconds to several minutes to print each page. Simple text documents are usually fast, but complex graphics can take a long time. You might be better off upgrading to a single workgroup-class network-enabled printer. -Richard I too have noticed mine being really slow when doing pictures or some complex graphics. Many people think printers are dumb but they still do a lot of processing. If the printer is old, you may want to see if you can upgrade the memory in it or just get you a newer printer. I have seen increasing the memory help a lot but it still depends on what you are doing and the speed of the processor. Is there a tool to monitor the use of USB ports? Maybe then he can see if it is the printer or the network. Maybe he already has done this and I missed it. Dale :-) :-) -- gentoo-user@gentoo.org mailing list
