Power limit vs Undervoltage

Hello there!
I have a gtx 1080, and I have found that power limit -10% does some effect as undervoltage by 10%, but when I use power limit some graphs looks really scarry (temparature in both cases goes -5 degrees)

image

and GPU no load limit, GPU power and GPU Core Clock graphs also unstable.

When I use undervoltage, all graphs seems like a line.

What approach is better for life my videocard? Is anyone have information about this case? What happens with GPU in both case and how dangerouse undervoltage can be?

Thanks in advance, Andrei!

That “scary” graph is just telling you if it is hitting the power limit or not. Just like how your hash rate is not 100% consistent, neither is your power usage. In this case 1=limited, 0=not limited. If you undervolt, it will be the same as “always 1”, whereas power limiting only shows 1 when the card’s usage tries to exceed the set limit.
I personally don’t undervolt, because there’s a chance (albeit slim) that the card will not register on the system, and then you have a brick. Power limiting does not do this, because the voltage is just prevented from going to a certain height.