hey all,
I have a render target, I changed the size form 4096 to (4096*2) which should be 8k.
This immediately caused the editor to start running at 4fps and displaying all sorts of artifacts everywhere - memory leak/something similar.
Any idea what I should look into?
Not sure if this helps with regards to RenderTargets but have you enabled 8k textures for your project?
http://www.environmentary.com/tutorials/how-to-enable-8k-textures-in-unreal-engine/
https://forums.unrealengine.com/development-discussion/rendering/101076-8k-textures-can-t-for-the-life-of-me-figure-out-how-to-enable-them?p=869810#post869810
I had - though I guess I better check it again since It was before I had to recover half the project due to some sort of autosave error.
I’m almost up to the 12 samples limits on the material, or my solution would be to just split the render targets into 4 and combine them within the material… what’s 20 extra instructions anyway when I’m up to 1600… 
it’s quite painful.