While benchmarking E-Cycles I found some renderings to be extremely slow and I did some tests as I though it might be related to E-Cycles, but it seems to be a general issue with 2.8x. It seems that Hilbert Spiral is ridiculously slow. The scene is pretty large (7000px x 7000px) has a decent amount of geometry and textures in it.

System information: Windows 10, GTX 980 Ti, 32GB RAM, Bucket size 250px x 250px.

Here are some benchmarks …

2.82EC - Right to left … 43 min.

2.82EC - Hilbert Spiral … Canceled after an hour (less than 50% rendered)

2.79EC - Right to left … 46 min.

2.79EC - Hilbert Spiral … 1 h 2 min.

2.82 Nightly - Right to left … 1 h 8 min.

2.82 Nightly - Hilbert Spiral … Canceled after 1 h 8 min. (less than 50% rendered)

The most obvious thing is that GPU memory steadily increases with Hilbert. At the point of canceling it was almost 6GB. With R2L the memory did not exceed 4GB.

I’d be interested to learn what that could be.