Messages in this thread | | | From | Paul Zimmerman <> | Subject | RE: [PATCH] usb: gadget: USB3 support to the legacy printer driver | Date | Tue, 18 Nov 2014 21:45:13 +0000 |
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> From: linux-usb-owner@vger.kernel.org [mailto:linux-usb-owner@vger.kernel.org] On Behalf Of Felipe Balbi > Sent: Tuesday, November 18, 2014 12:47 PM > > On Tue, Nov 18, 2014 at 03:41:43PM -0500, Jorge Ramirez-Ortiz wrote: > > > > notice that the original PLX driver was still far from the theoretical 5Gbps > > target (I was expecting to measure at least 3Gbps and could only get 1Gbps). > > So 1Gbps should be the target to meet on the kernel.org net2280 - do you agree? > > this depends on a whole bunch of things. Mainline is a lot different > from PLX's kernel tree, I'm sure. > > It also depends on how many PCIe lanes you're using. Just because USB3 > guarantees 5Gbps bandwidth, if you use a 1x PCIe connector, you'll never > get that ;-)
Being pedantic, USB3 runs at 4Gbps, not 5Gbps. The signal transitions on the bus are at 5GT/s (5 giga-transitions per second), but due to the 8b/10b encoding, that equates to 4Gbps data rate.
-- Paul
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