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Using the supplied FX2_SDRAM.CyUSB.cpp and FX2_SDRAM.EzUSB.cpp host applications, modified for sending/receiving a variable number of words, I have the following results:

Using EzUSB: 8192 bytes send, 8192 bytes receive:, 2.093 seconds => 7.83 KB/s
Using CyUSB: 8192 bytes send, 8192 bytes receive:, 4.156 seconds => 3.94 KB/s

Looks like EzUSB is about twice as fast. I'd like to hear about any better results.

It looks like the Xylo is running as a Full-speed USB device, with a signaling bit rate of 12 Mbps, in this application. Changing to a USB 2.0 port made no difference.

The USB/SDRAM demo is not optimized for speed - since we write only one word in the SDRAM at the time, that makes very small USB packets and creates lots of overhead.