Although I'm still not completely understanding the definitions of SPU offloading and nTurbo (IPS engine related?) offloading, I can tell one thing: those numbers are percentages of the total sessions at the time. So basically higher is better, like 90%. It's not percentage of the SPU/nTurbo capacity.
The Fortinet Security Fabric brings together the concepts of convergence and consolidation to provide comprehensive cybersecurity protection for all users, devices, and applications and across all network edges.