67% savings. If an application reads a 1MB file the normal way, the kernel creates 1MB of buffers in the file system cache to hold the data. Then it copies the data to another 1MB of buffers which are owned by the application. If the application then writes the data out to a network socket, the kernel has to allocate another 1MB buffer to hold the data while it is being sent.
If the application were processing the data in some way, then it would be worth it. Otherwise it is better to skip all of that work.
If the application were processing the data in some way, then it would be worth it. Otherwise it is better to skip all of that work.