BFD ASIC Question

Hello 

We are trialing 501E's for PoC for a project, can anyone firm that when using BFD, is the BFD traffic processed by the CPU or sent to the ASIC. The testing we have done so far with Ixia's seems to point BFD being processed by the CPU as when we pump large amount of 64 byte or 128 byte tcp packets, the CPU goes to 97-98% usage and then BFD fails and pulls down BGP, surely if BFD was at the ASIC level it wouldn't be affected by the CPU usage ?