3 ms·

I think in our modern age, a lot of people can be surprised at just how fast the CPU is relative to GPU. Slower, yes, but compiled SIMD-enabled CPU code is bloo

I think in our modern age, a lot of people can be surprised at just how fast the CPU is relative to GPU. Slower, yes, but compiled SIMD-enabled CPU code is bloody fast. I've seen people on HN claiming "just put it on the GPU and be 10,000x faster"; I can only assume this comes from comparing interpreted Python code with compiled kernel code or something! Basic drawing code is highly likely to be memory-bandwidth-bound; Some napkin math shows e.g. a 4070 has about a 10x performance advantage over a Zen4 CPU (500gb/s vs 50). Rant out of the way, obviously 10x faster is still an order of magnitude faster! I've continued to be curious if there's a way to properly batch geometry in the QT backend to remove all the state-changes that the QT painter is doing that kill performance; a powerfully GPU-accelerated backend for widget based apps would be incredibly useful, although given the dominance of web/electron apps these days not a useful feature for a commercial company to build.

SubjectToChange 3y ago
There has been more and more “GPU chauvinism” over the past decade. For whatever reason many people have come to see the GPU architecture as the pinnacle of modern computing, seemingly unaware of its limitations. Although CPUs are boring in comparison, they most often don’t require special toolchains, shader languages, near and far memory, etc. Moreover, SIMD instruction sets like AVX-512 or SVE2 offer extremely impressive performance, often negating the need for a GPU altogether. Of course this isn’t to be dismissive of GPUs, they are a welcome addition to the compute stack. But the humble CPU should not be underestimated.