I was able to achieve ~320 Mbit/sec data rate using the Gigabit System Reference Design (GSRD XAPP535/536) from Xilinx.  This utilizes the LocalLink TEMAC to perform the transfers.  The reference design provides the Linux 
2.4 drivers that can be ported to Linux 2.6 with a little effort.&nbsp; <br><br>This implementation did not use checksum offloading and the data rates were achieved using TCP_STREAM on netperf.<br><br>Greg<br>