This is an interesting writeup on various ways to speed up your application. This is useful if you are getting into HPC for the first time. The author POR IVICA BOGOSAVLJEVIĆ suggested various ways

• Distributing workload to multiple CPU cores
• Distributing workload to accelerators
• Usage of vectorization capabilities of your CPU
• Optimizing for the memory subsystem
• Optimizing for the CPU’s branch prediction unit

References:

• Many ways to speed up your program by Appentra