> Now imagine a parallel universe where instead of focusing on making asynchronous IO work, we focused on improving the performance of OS threads such that one

> Now imagine a parallel universe where instead of focusing on making asynchronous IO work, we focused on improving the performance of OS threads such that one can easily use hundreds of thousands of OS threads without negatively impacting performance Isn't that why async I/O was created in the first place? > Just use 100 000 threads and let the OS handle it. How does the OS handle it? How does the OS know whether to give it CPU time or not? I was expecting something from the OP (like a new networking or multi-threading primitive) but I have a feeling he lacks an understanding of how networking and async I/O works.