>>533696797
How exactly is it calculated then? The wiki gives the following formula for damage received: (1 - Suit resistance) x (1 - Art. resistance) x 100%. So if you've got 60 suit armour and 20 artefact armour, you're going to get:
(1-0.6) x (1-0.2) x 100% = 32% of the damage, which means 68% is negated, only 8% more than if you wore no artefacts at all.
If you know a different formula, or where to look for it in the game files, please tell.