I've seen a bunch of guides that say for BvB using Grief Zerker the min ias you need on it is 34%.

Is that still the case or has something changed with the previous patches where the way ias works has been reworked. I know it has changed dramatically for melee druids but not sure about barb.

Anyone know the answer to this?

You need 63 total ias for max ww speed on a 0 speed weapon now.

Before ww was only calculated from the weapon, now your total ias is important.
So to reach 4frames you need 63ias total. that means, you need at least 2 ias jewels, total 30. To reach 63, you will need 33min ias on grief. Or of course you can use other items, like highlords, or ias glove or whatever. Of course this is for grief zerker,
if you use zwei grief, then you will need 42 ias, which means you will need 1 ias jewel.

Thanks