raphlinus.github.io

> PS, is your monoid work online, is it this https://arxiv.org/abs/2205.11659 ? I'm interested in monoids on GPUs. Yes, that's the draft on arXiv, and I have a blog post in the pipeline[1] explaining it to a more general audience. And thanks for the other advice, I'll consider it! [1] https://github.com/raphlinus/raphlinus.github.io/issues/66

The short answer is no, but the long answer is that this is a very complex tradeoff space. Going forward, we may see more of these types of tasks moving to GPU, but for the moment it is generally not a good choice. The GPU is incredible at raw throughput, and this particular problem can actually implemented fairly straightforwardly (it's a stream compaction, which in turn can be expressed in terms of prefix sum). However, where the GPU absolutely falls down is when you want to interleave CPU and GPU computations. To give round numbers, the roundtrip latency is on the order of 100µs, and even aside from that, the memcpy back and forth between host and device memory might actually be slower than just solving the problem on the CPU. So you only win when the strings are very large, again using round numbers about a megabyte. Things change if