Ezequiel Garcia <elezegarcia@xxxxxxxxx> writes: > Very interesting. Let me see if I understand this: you say it's not a > problem with USB bandwidth, but with isochronous transfers, in the > sense it could achieve enough speed for streaming if bulk transfers > were used? It is more of a hope than a statement... I have no proof. > Do you have any links supporting this? Only old stuff like http://www.mail-archive.com/linux-usb@xxxxxxxxxxxxxxx/msg04232.html There are quite a few reports of problems with USB cameras in general and Kinect in particular. That seems to point at problems with isochronous transfers. A typical USB camera does not need particularly much bandwidth. The Nanostick only needs 40Mbps + overhead for me -- the size of the largest MUX in the UK currently. That is less than 10% of the 480Mbps theoretically available. The other problem reports tend to be about "full speed" (11Mbps) USB devices which are difficult for the Pi hardware to handle. Most of the reports are getting old, some have reported that driver upgrades fixed the problems. I believe most people experience stable ethernet performance (and the ethernet is USB attached as you are undoubtedly aware). That is a lot more demanding than a USB camera or a Nanostick. However, the ethernet chip uses bulk transfers, not isochronous ones. /Benny -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
