Is there difference between 70k and 100k armour?

I already have 90% phys dmg mitigation at 70k armour is there any point getting 100k armour? does it change anything

Yes, there is absolutely a difference when it comes to taking big hits. Armour has some hidden limitations on how much actual damage reduction you get which is based on the hit damage. I'd strongly advise reading through the wiki page.

https://www.poewiki.net/wiki/Armour

It does.

If you are defending from physical hit with only armour:

Outgoing damage 10 000
Armour 70 000

Incoming damage reduced by = 70000/(70000+5*10000) = 0.583

So you would take (1-0.583)*10000=4170 damage after mitigation from armour


In case where Armour ir 100 000:

Incoming damage reduced by = 100000/(100000+5*10000) = 0.666

So you would take (1-0.666)*10000=3340 damage after mitigation from armour


I have rounded some numbers but should be good enough to convey the message.
All relevant formulas are on poewiki.net/wiki/armour

i see thanks good to know but what about evasion if i have 90% chance to evade theres no point getting more evasion?

You have 90% evasion against baseline accuracy monsters if your ingame stats show 90%. But there are monsters that come with extra accuracy granting modifiers. There are also map mods that reduce evasion rating.

In case when fighting against such things or in such maps you may want to have more evasion.

EDIT: you also you no evasion vs deadeye mobs, yay CW vision.

Unless its cheap there isn't much point in going from 70k to 100k armour you'd get more out of making your life pool bigger for example. Basically its all passive efficiency or whatever you want to call it.

If you are running Aegis aurora or the armour works vs ele damage timeless jewel its a little different but once you get to a certain value of armour you'd get far more out of straight physical damage reduction, endurance charges, phys taken as elemental etc than more armour.

Evade caps at 95% I believe at which point increasing it doesn't do anything for you aside from making its value higher vs accurate monsters (but its hard to notice this and you won't be told the value). 95% evade makes the game feel pretty broken if you've got enough layers to survive the occasional hit that gets through.