"slow render"

So, I’m rendering a rather large project, which is not unusual.
My frametime is around 2min per frame on CUDA, but at the ender of each frame it stalls at “Writing output: done” for maybe 10mins.

I’m using vray 5 GPU on CUDA with max 2021. Also using renderstack to manage the scene.

An update to my own troubleshooting. I have tried switching it over to vray raw image file and it still stalls completely at the writing output or similar. At the same time it is using 100% CPU.

I found out the problem, nothing to do with vray. I had a tyflow-sim that it was constantly calculating.