Huge increase of memory use when increasing the resolution I've been struggling to render an interior scene (pic below), which I don't think is very complex, around 2,5M of vertices. As I had many problems running out of memory, I had to do some optimisations, this is what I've done:


Render with the CPU (It would take 50 hours)
Get rid of a couple Adaptive Subdivision and use regular Normal Maps. Now I only use it for the carpet.
Reduce some levels of most of the Subdivision modifiers in some secondary objects.
Use 1K textures instead of 3k for most objects.
Decrease the resolution to 1980x1250px.


With these tweakings I managed to reduce the poly count to 1,7M and, most importantly, to render the entire scene using around 4GB (I have a 1060 6GB, so there's no much room).

I tried to increase the resolution to see how much I can get, so I've tried to increase it by just 15%. When starting, the memory usage is higher but no errors, it's still below 4.7GB which It's the limit for my graphics card. But when it reaches a specific tile the memory usage increases to... 22GB!

Why does increasing the resolution this little produce a huge difference?

This is the scene:



And here's the screenshot of the error:



The .blend file is(90MB)

I've uploaded it to Dropbox, here's the link.

Thanks in advance,
If you see memory usage changing while rendering, it could be because of Denoising enabled, try:


lowering the render tile size
changing the tile order (from Hilbert to Left-to-right), so the minimum number of tiles are kept in memory
disabling Denoising altogether


Explanation why extra memory has to be used for denoising is here:

Why does Denoising take up so much memory?