与网络/ io绑定应用程序的进程相比，Linux上的线程限制是什么?

I've heard that under linux on multicore server it would be impossible to reach top performance when you have just 1 process but multiple threads because Linux have some limitations on the IO, so that 1 process with 8 threads on 8-core server might be slower than 8 processes.I've heard that under linux on multicore server