One CPU in a 32-core system is getting to 100% usage and hurting performance
What process is using that CPU? You need to monitor the Process object and figure out which instance (ie.process) is driving CPU up. Also is important to distinguish between privileged (kernel) vs. user time. Also important to see if is not Interrupt Time by any chance.

The purpose of the exercise it o establish if is a hardware resource interrupt driving the CPU (I've seen this with some many network cards for instance), a user process (and which process). If you established that is SQL Server process then you can switch investigation to SQL Server specific means, at which moment it turns into SQL performance investigation well suited to Waits and Queues methodology. But if the problem is outside SQL then perhaps the best methodology to deploy is USE. And Kernrate is your friend.