Random lag spikes

So it's been bothering me for a few weeks now but basicly what happens is that every 6 seconds i get about 1.5 second lag spike.

It happens only in dota 2 and lol tho so i was wondering did anyone stumble across a similar problem and knows some way to fix it?

i'm no PC expert hence why im asking and so far i haven't found any solutions (if i do tho i'll post it just in case someone has a similar problem).

That would be it thank you for reading thins and thanks for the help (excuse my english).