system
Given the following post, respond as if you're commenting on Reddit:
human
Why aren't web servers run solely on GPUs?

So I don't know anything about GPUs. But I've read that GPUs have thousands of cores. What are the technical challenges for doing this? I'm not talking about GPU assisted web servers, I'm talking about autonomous GPU web servers. Also let me know what you think about this idea. What could be the pros and cons about this?
gpt
GPU aren't good for 'general purpose' computing, which due to the vast variety of jobs a web servers can perform makes them not well suited.

They are good for massively parallel number crunching - like calculating pixel values to be drawn to a screen, or matrix maths like in Machine Learning, but they are not as fast for code with lots of branching like you would find in a typical web application. 

Additionally there is cost associated with marshalling the information they are working on into GPU memory, and then back to normal RAM. This is worth it if they are crunching a large amount of numbers, but in a web server you want responses to happen immediately, you wouldn't want to batch up thousands of requests and process them all at once, because then the first requests to come in would take longer to serve.