Let's do some back of the envelope here... 10Gbps/(8*1500bits/pkt) = 833333 pkts/s
1e9 cycles/s /833333 PKs/s = 1200cycles/pkt
So there's on the order of a few thousand cycles to copy the packet to the kernel, decide on it's fate and send it to the NIC and that's assuming max sized packets. To make this work you will want quad core and 2GHz minimum, and something modern, probably you can do it with an i5 or so but not much less.