On Wed, 26 Aug 2009, cihan öztürk wrote: > Hi, > According to our results maximum throughput of our protocol is about > 1.58 Mbps per device. Connecting more than one devices on the > same or different buses(root hubs) doesnt change this maximum limit. > 1.58Mbps makes almost 200bytes per frame, which makes 3 full bulk > transactions (64 each at full speed) plus one partially filled. > I wonder if UHCI controller pads the empty bytes of 4th transaction > with dummy data or not. No, it doesn't. > I am asking this question because 4 transactions > make about 2Mbps. But when we try this throughput, although the device > almost manages to process all submitted requests, > we get a lot of outliers (which is what we called a urb transmission with > latency more than 1ms). 200bytes per frame is ideal in terms of outliers, > much lower than %1, and request processing rate(%100). > So, do you have any ideas about this issue? You'll have to post the usbmon log. I can't say anything useful without seeing it. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
