> […] smb file sharing, most of CPU power consumes the app, not network.

This I didn't expect with file sharing. What's there beside the networking that consumes so much CPU?

> ideal solution will be to utilize NIC hardware acceleration and encryption engines
> in X1000 and X5000 CPUs ( maybe Sam460 too, SEC engine there was optional )

Are the encryption methods offered by those 10 to 15 years old hardware engines still relevant in today's networking anyway?
Another way to better network performance would be a network stack with modern features and with a new "SANA-III" interface to the driver level.

> X1000 and X5000 has FPGA, it can be SEC engine too.

Almost. X1000 and X5000 have a CPLD, which I don't think would suffice for such purpose.