ArP + Sunder Armor

[Tobacha]

I have my ArP at 80% now so I was wondering if the extra 20% added with sunder armor made it 100%?
http://www.wowarmory.com/character-s...il&cn=Grellgar. Thx guys.

[Fledern]

No they are different mechanics. Sunder armor effectively "removes" armor. For everybody. Armor penetration ignores - for YOU ONLY - a percentage of the REMAINING armor.

So why is Sunder Armor still important? Because ArmorPen still has a cap. Even if you have 100% ArP, the boss will have some armor remaining. Sunder Armor drops Boss armor to below cap at which point you can achieve a "lol no armor" state.