star-like patterns formed by arrays of cubes in viewport I noticed these patterns:

The mesh you see is just the base cube duplicated 1000 times in x and y directions using an array modifier, spacing is 1.2.
This is no problem, I am just curious what causes this. Would I see this in real world as well, if I had 1000000 little cubes evenly spaced in front of me, or is this the result of the computing. I tried rendering this view, to see if this remains in the render as well, and it does, but the effect is way more subtle.
I know this question is kind of off topic, but I am really curious...
Yes, you would.  Those are known as "Moire patterns" and they occur in real life.  The wikipedia page goes into great detail:

https://en.wikipedia.org/wiki/Moir%C3%A9_pattern

You can even see it in this photo of a normal striped shirt!