Which part of test results to check for tcp_ip related improvements?

[diesel2]

I have been reading up on some optimization methods for TCP/IP, particularly because I am stuck on an Ubuntu 14.04 LTS server where HTTP 2.0 is not possible, at least without using an external PPA, if I recall correctly.

So, these TCP/IP optimizations would at least give me some improvement until I can move to Ubuntu 16.04 or higher.

But, what I can't figure out is where these improvements will reflect in the test results. In TTFB or the number of HTTP request or anywhere else?

Any pointers would be most welcome.