Multithreading and the Memory Subsystem

Multithreading and the Memory Subsystem

In this post we investigate how the memory subsystem behaves in an environment where several threads compete for memory subsystem resources. We also investigate techniques to improve the performance of multithreaded programs – programs that split the workload onto several CPU cores so that they finish faster.

The memory subsystem from the viewpoint of software: how memory subsystem affects software performance 2/3

The memory subsystem from the viewpoint of software: how memory subsystem affects software performance 2/3

We continue the investigation from the previous post, trying to measure how the memory subsystem affects software performance. We write small programs (kernels) to quantify the effects of cache line, memory latency, TLB cache, cache conflicts, vectorization and branch prediction.

When vectorization hits the memory wall: investigating the AVX2 memory gather instruction

When vectorization hits the memory wall: investigating the AVX2 memory gather instruction

For all the engineers who like to tinker with software performance, vectorization is the holy grail: if it vectorizes, this means that it runs faster. Unfortunately, many times this is not the case, and the results of forcing vectorization by any means can mean lower performance. This happens when vectorization hits the memory wall: although…