Problems with pushing higher than 115 in a group

The issue is lag. I use a rend barb with no area damage but one of my high level experienced clan mates tells me simply using that build is going to cause massive lag even if I remove area damage.

I want to push higher, 120 or more, with a friend who has a 2000 paragon crusader. My more experienced clan mate suggested the idea of me going zbarb and just doing a two man but I want to hear different opinions on what to do, in particular in a four man group.

I don’t really have a good understanding of the group meta and I’m not sure how other players do higher level grs without lag issues. Is it because they can kill stuff quickly before it lags or is the problem just the rend barb in itself? I don’t really know. Would appreciate help.

Rend isn’t the problem causing lag, it’s the whirlwinds hitting monsters.
(This assumes you don’t ANY source of Area Damage to make the situation even worse.)

So is the solution to reducing/removing lag being able to kill mobs quick enough or do I have to ditch my rend barb and go something else?

AFAIK, WW/Rend barbs aren’t used in any “META” groups.

But nevertheless, lag is most always a problem in group runs,
no matter which classes participate, especially since “META” runs
tend to clump up huge amounts of Monsters in tight spaces.

Lag AFAIK is a D3 SERVER problem. They aren’t able to handle the
large amount of constant damage calculations per second efficiently.

I just got told recently Physical damage can cause lag and I should switch to Lightning. Can anyone confirm?

There’s a small part of truth to that, kind of. The Lightning rune of Rend is used to manually apply rend instead of auto-applying it (in GRs > 130 solo).
How great the overall effect of that change really is in a group, remains to be proven.