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libusb-win32-devel
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From: Dan E. <Dan...@ne...> - 2006-03-06 13:27:44
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Black Moon wrote: > Hi, im trying to do large bulk transfers to a full speed USB device > (12mbit) Yet even in a dead loop, at best iv gotten 1.6mbps (yes, > bits per second) with 2k transfer sizes. Think I might get any better > with async? My device atm is a pic18f4550 without ping pong buffers > enabled but id assume I should get better then 1.6mbps even without > them (Unless maybe its stalling?) and the pic isent actualy doing > anything with the data. 64byte buffer on the pic side Is async even > complete enough to use at all? When is 1.0 due out anyway? And I > can't even seem to find any documenation about async :( I really > don't want to have to go to using the DDK directly. =20 Sounds like there's something wrong with your setup. You should get better performance than that. I'd definitely try enabling ping pong buffers though. The host will be trying to send the next packet immediately and your device won't be able to receive it because it's only just got the last one. This will immediately halve your rate, and possibly worse if the host backs off on the endpoint. Dan. |
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From: Stephan M. <ste...@we...> - 2006-03-06 18:45:11
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Here are some values I get with one of my test programs using the synchronous API and an old 8051 Cypress full speed chip (double buffering enabled, 64 bytes endpoint buffer): - the second column is the transfer size in bytes - the third column is the throughput in kbytes/s bulk write | 64 | 32 bulk write | 640 | 312 bulk write | 6400 | 892 bulk write | 64000 | 1041 bulk write | 640000 | 1031 bulk read | 64 | 31 bulk read | 640 | 312 bulk read | 6400 | 893 bulk read | 64000 | 1041 bulk read | 640000 | 1031 interrupt write | 64 | 32 interrupt write | 640 | 56 interrupt write | 6400 | 61 interrupt write | 64000 | 62 interrupt write | 640000 | 62 interrupt read | 64 | 31 interrupt read | 640 | 56 interrupt read | 6400 | 61 interrupt read | 64000 | 62 interrupt read | 640000 | 62 > > Hi, im trying to do large bulk transfers to a full speed USB device (12mbit) > Yet even in a dead loop, at best iv gotten 1.6mbps (yes, bits per second) > with 2k transfer sizes. Think I might get any better with async? My device > atm is a pic18f4550 without ping pong buffers enabled but id assume I should > get better then 1.6mbps even without them (Unless maybe its stalling?) and > the pic isent actualy doing anything with the data. 64byte buffer on the pic > side > Is async even complete enough to use at all? When is 1.0 due out anyway? And > I can't even seem to find any documenation about async :( I really don't > want to have to go to using the DDK directly. > > > > > ------------------------------------------------------- > This SF.Net email is sponsored by xPML, a groundbreaking scripting language > that extends applications into web and mobile media. Attend the live webcast > and join the prime developer group breaking into this new coding territory! > http://sel.as-us.falkag.net/sel?cmd=lnk&kid=110944&bid=241720&dat=121642 > _______________________________________________ > Libusb-win32-devel mailing list > Lib...@li... > https://lists.sourceforge.net/lists/listinfo/libusb-win32-devel ______________________________________________________________ Verschicken Sie romantische, coole und witzige Bilder per SMS! Jetzt bei WEB.DE FreeMail: http://f.web.de/?mc=021193 |
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From: Black M. <bla...@ho...> - 2006-03-07 04:02:41
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Thanks, i'll try messing around with the pics buffering some more >From: Stephan Meyer <ste...@we...> >Reply-To: lib...@li... >To: lib...@li... >Subject: Re: [Libusb-win32-devel] Full speed bandwidth? >Date: Mon, 06 Mar 2006 19:44:53 +0100 > > >Here are some values I get with one of my test programs using >the synchronous API and an old 8051 Cypress full speed chip >(double buffering enabled, 64 bytes endpoint buffer): > >- the second column is the transfer size in bytes >- the third column is the throughput in kbytes/s > > >bulk write | 64 | 32 >bulk write | 640 | 312 >bulk write | 6400 | 892 >bulk write | 64000 | 1041 >bulk write | 640000 | 1031 >bulk read | 64 | 31 >bulk read | 640 | 312 >bulk read | 6400 | 893 >bulk read | 64000 | 1041 >bulk read | 640000 | 1031 >interrupt write | 64 | 32 >interrupt write | 640 | 56 >interrupt write | 6400 | 61 >interrupt write | 64000 | 62 >interrupt write | 640000 | 62 >interrupt read | 64 | 31 >interrupt read | 640 | 56 >interrupt read | 6400 | 61 >interrupt read | 64000 | 62 >interrupt read | 640000 | 62 > > > > > Hi, im trying to do large bulk transfers to a full speed USB device >(12mbit) > > Yet even in a dead loop, at best iv gotten 1.6mbps (yes, bits per >second) > > with 2k transfer sizes. Think I might get any better with async? My >device > > atm is a pic18f4550 without ping pong buffers enabled but id assume I >should > > get better then 1.6mbps even without them (Unless maybe its stalling?) >and > > the pic isent actualy doing anything with the data. 64byte buffer on the >pic > > side > > Is async even complete enough to use at all? When is 1.0 due out anyway? >And > > I can't even seem to find any documenation about async :( I really don't > > want to have to go to using the DDK directly. > > > > > > > > > > ------------------------------------------------------- > > This SF.Net email is sponsored by xPML, a groundbreaking scripting >language > > that extends applications into web and mobile media. Attend the live >webcast > > and join the prime developer group breaking into this new coding >territory! > > http://sel.as-us.falkag.net/sel?cmd=lnk&kid=110944&bid=241720&dat=121642 > > _______________________________________________ > > Libusb-win32-devel mailing list > > Lib...@li... > > https://lists.sourceforge.net/lists/listinfo/libusb-win32-devel > > >______________________________________________________________ >Verschicken Sie romantische, coole und witzige Bilder per SMS! >Jetzt bei WEB.DE FreeMail: http://f.web.de/?mc=021193 > > > >------------------------------------------------------- >This SF.Net email is sponsored by xPML, a groundbreaking scripting language >that extends applications into web and mobile media. Attend the live >webcast >and join the prime developer group breaking into this new coding territory! >http://sel.as-us.falkag.net/sel?cmd=lnk&kid=110944&bid=241720&dat=121642 >_______________________________________________ >Libusb-win32-devel mailing list >Lib...@li... >https://lists.sourceforge.net/lists/listinfo/libusb-win32-devel |
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