we should know in a month or two how the 3d cache will do
but i'll have it under water so it should be fine
i will need a new block as i'm sure the solid copper bar it got on the threadripper won't work
and may not any of the current am4 waterblocks without new mounting as it maybe a taller chip
The issue with the cache+die changes is that your cooling doesn't matter - the limitation becomes the ability of the IHS to transfer the heat to your cold-plate. That's why the 5000 series will still hit 80c even with a custom loop. The thermal density is high and thermal transfer is the limiting factor.
The stacked cache and shaved die will only make that worse, unless they came up with some new method, but everything I've read says they know that the thermal transfer capabilities will be worse - hence the reduced core speeds.
They've said the chip height is not changing, so all AM4 blocks will work. That's the "Z-Height" that was referred to.