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Re: slow transfers to a full-speed device

Unfortunately not. I did notice the previous emails concerning the G5 architecture changes, wherein the controller had to traverse memory in order to find pending work... adding inter-packet delays. I suspect this is not coming into play, unless the G4 iBook has the same issue... may be time to try to come up with bus analyzer...

Thanks,
Eric
On Jun 14, 2005, at 9:15 PM, Fernando Urbina wrote:

Do you have a bus trace? I think this is what you need. A bus trace in Windoze would also be helpful.

--
Fernando Urbina
USB Technology Team
Apple Computer, Inc.

On Jun 14, 2005, at 9:52 PM, Eric Smith wrote:


I've got a full speed USB device, and am writing data in 64 byte packets to a bulk endpoint. This is just sitting in a for loop, doing a bunch of WritePipe() calls. My download speed over several megabits is only about 500Kbps. I'm using Tiger, and a dual 1.8 G5. I get about the same performance on a G4 iBook running Tiger. The same USB device gets about 6Mbps download on a windows-based machine. I did not write the windows code, so I don't know any of the details of that implementation.

Any ideas or suggestions?





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 >slow transfers to a full-speed device (From: Eric Smith <email@hidden>)
 >Re: slow transfers to a full-speed device (From: Fernando Urbina <email@hidden>)



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