USB Speeds


I'm using the Beagle board(Angstrom) USB OTG as a peripheral and
connecting it to a Linux PC(Fedora 9). After I connect the two and
start the USB networking(NDIS) between the two, it looks like I am
getting a speed of ~100-105 mbps from BB to host and ~30-35 mbps from
host to BB. I'm just sending raw packets between the two with no
Ethernet/IP/UCP/TCP headers, so there shouldn't be any checksum
overhead with the packets.

Is this the max rate that the USB on these can go? I'm running data
in one direction at a time, so it's not a full duplex data path. The
linux on board is running runlevel 3, so there's no extra CPU on X.

Are there settings that can be tweaked for this(such as /proc or /sys
files), or should I be using a different method to transfer(stream)
data from an app on the bb to the host?

Just a note. I can get about 4.5MB/S over NFS (TCPIP over Ethernet over USB) here.
I use “time cat bigfileOnHost > /dev/null” to check speed.
Use “time dd if=bigfileOnHost of=/dev/null bs=512” or bigger seems give me much faster speed (too fast to be true).