Thank you so much for this Vigz. It's the only solution I've found to be helpful. I have intel 3160 wireless card and now everything works smoothly, without lags and spikes.
I wish there were more people like you, since everyone else just threw some random solutions like changing the power management, increasing aggressiveness or changing channels of the wifi and so on, without even looking checking the problem. You described everything about the problem and solution.
Thank you again!!!