Speed

All results are from one console uploading from PC to Xbox; the adapter rows use a TP-Link UE306:

Setup	Speed
Normal FTP, Xbox’s own 100 Mbit port (no adapter)	at most about 10.5 MiB/s
Aurora’s built-in FTP, CUsbEnet 1.0	about 19.5 MiB/s
FastFTP network test, CUsbEnet 1.0	about 20.7 MiB/s
FastFTP network test, NetUsb360 1.1 acksmall, all data checked	27.66 MiB/s
FastFTP upload, NetUsb360 1.1 acksmall	about 28 MiB/s

The maintainer has also seen up to 29 MiB/s FTP uploads with this combination.

For comparison, the console’s internal hard drive writes at about 57.5 MiB/s (measured on the same console), so it is not the limit. The 12x DVD drive reads at most about 15.9 MiB/s (rated speed at the outer edge of the disc, not measured), so FastFTP over NetUsb360 copies faster than the console can read a disc.

What changed in 1.1

• Bigger receive transfers. The AX88179 now hands data over in 24 KiB USB transfers instead of 16 KiB, the same as Linux uses on USB 2.0.
• Batched delivery. Received packets go to the network stack in batches instead of one at a time.
• ACK batching (acksmall build only). While uploading, the Xbox sends a stream of small acknowledgements, and each one used to cost a full USB transfer.

More streams, bigger socket buffers and even larger receive transfers made no real difference. At this point the driver uses about 15% of one CPU thread while receiving, so the limit is the Xbox’s USB 2.0 controller and not the driver.