QuoteOriginally posted by: mjindeed threads in the same half-warp are essentially in a SIMD architecture situation.The relation between them is not so simple.SIMT GPU SIMD"Programmable NVIDIA GPUs are very inspiring to hardware geeks, proving that processors with an original, incompatible programming model can become widely used.NVIDIA call their parallel programming model SIMT - "Single Instruction, Multiple Threads". Two other different, but related parallel programming models are SIMD - "Single Instruction, Multiple Data", and SMT - "Simultaneous Multithreading". Each model exploits a different source of parallelism: In SIMD, elements of short vectors are processed in parallel. In SMT, instructions of several threads are run in parallel. SIMT is somewhere in between ? an interesting hybrid between vector processing and hardware threading.My presentation of SIMT is focused on hardware architecture and its implications on the trade-off between flexibility and efficiency. I'll describe how SIMT is different from SIMD and SMT, and why ? what is gained (and lost) through these differences."