CRAFFT: high resolution FFT accelerator in spintronic computational RAM

High resolution Fast Fourier Transform (FFT) is important for various applications while increased memory access and parallelism requirement limits the traditional hardware. In this work, we explore acceleration opportunities for high resolution FFTs in spintronic computational RAM (CRAM) which supports true in-memory processing semantics. We experiment with Spin-Torque-Transfer (STT) and Spin-Hall-Effect (SHE) based CRAMs in implementing CRAFFT, a high resolution FFT accelerator in memory. For one million point fixed-point FFT, we demonstrate that CRAFFT can provide up to 2.57× speedup and 673× energy reduction. We also provide a proof-of-concept extension to floating-point FFT.