Yep, that's what seems to be the case. The whole point of PCIe is lower latency -- with a frame size that large I can get lower latency w/ 10 GbE and 500B frame size. I can't imagine it is a large effort to get that fixed :)
_______________________ Eugene Grayver, Ph.D. Aerospace Corp., Principal Eng. Tel: 310.336.1274 ________________________ -----Original Message----- From: Marcus Müller [mailto:marcus.muel...@ettus.com] Sent: Monday, September 24, 2018 11:41 AM To: Eugene Grayver <eugene.gray...@aero.org>; usrp-users@lists.ettus.com Subject: Re: [USRP-users] PCIe driver frame size Hi Eugene, I'm not an expert on the PCIe transport, but as far as I can tell from 3.11.0.1's uhd::transport::muxed_zero_copy_if::sptr make_muxed_pcie_msg_xport the PCIe frame sizes seem to be immutable (4 kB, in fact, which, subtracting header and dividing by sample bitwidth, leads to 1020 samples per frame). Best regards, Marcus On Fri, 2018-09-21 at 18:32 +0000, Eugene Grayver via USRP-users wrote: > Is there a way to specify the frame size on the PCIe interface? I > tried using the same keywords as for the NIC, but it had no effect. > I need low-latency and the default frame size is 5000 bytes (much too > large for my needs). > > _______________________ > Eugene Grayver, Ph.D. > Aerospace Corp., Principal Eng. > Tel: 310.336.1274 > ________________________ > > _______________________________________________ > USRP-users mailing list > USRP-users@lists.ettus.com > http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com _______________________________________________ USRP-users mailing list USRP-users@lists.ettus.com http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com
