20k ram versus 128k ram 128k flash versus 512k flash 72 Mhz CPU versus 100 Mhz CPU Cortex M3 versus Cortex M4Amazingly, the Cortex M4 has single precision floating point, which I am unlikely to ever use or care about. The big deal is the increase in memory.
The F411 supports only 3 endpoints rather than 16 as does the F103. In general I am unlikely to care, but this could be important if you wanted to design some gadget that acted like several USB devices, as is sometimes done.
The F103 has 512 bytes of USB packet memory.
The F411 has 1.25 Kbytes of USB packet memory.
The F411 has a very different USB subsystem. It is some version of the Synopsys OTG_FS controller for USB 2.0. This is usually a nightmare because the Synopsys documents are unavailable, but in this case there seems to be decent documentation as part of the TRM for the F411. That over 100 pages of the 900 page TRM are devoted to this peripheral makes us very happy. It is the Synopsys USB 3.0 controllers that are undocumented.
Tom's Computer Info / tom@mmto.org