Today I did a brief empirical test, after having read alternative posts on the Internet Ocean
I tried to lower the buffer to the lowest level, but the system refused to go lower than 32 samples 
With 32 samples I had a very low latency…
But my CPU got angry and started to hiss and growl 
I found anyway that the difference between 256 and 2048 samples is not so high as I expected, as far as I don’t use too many CPU-sucker plugins
I also tried the internal audio-card with its Realtek High Definition Audio Driver that is supposed to be better than the external audio-card’s driver because it is an Asio driver and it avoids having 2 ASIO drivers in the same OS, but it was not recognized by my DAW, so I cannot tell if it is really better/doable
I also wanted to test the WASAPI exclusive driver, but Ableton Live does not support it, YUK
Cantabile supports it, so I am curious to see 
LatencyMon report:
I tried FlexAsio and I found that my CPU was less stressed, but at the cost of some noise with certain plugin (UJAMs)
Now I’ll try Asio4all just to complete the round
Well, Asio4all is better: less CPU used than the Komplete Audio ASIO driver 
And I have the further option to lower the In/Out Sampling frequency reducing further the stress on CPU…
The only con’s is a hiss closing/opening a project containg certain plugins
I am starting to think that the unofficial ASIO drivers give you more options but at the cost of less stability
Well, tried Wasapi, but the audio-card ASIO is better 
In Italy, we say: uomo avvisato mezzo salvato 
(forewarned is forearmed)