Hi,
I have been rendering a scene, it takes only 5 seconds to render per image when the camera is set to HD 1080 image. But as soon as I dial HD 2160 in my camera, the render takes 5 minutes and half. I find it weird. Can someone point into right direction how make it to 20 seconds, which would be normal, according to my mathematical knowledge? (HD 2160 has 4 times more points, shouldn't render take only 4 times longer?)
Cheers!

Ditch Mantra and use Redshift

AndyW
Ditch Mantra and use Redshift

Sounds great but no budget for the license and especially no budget for any decent graphic card. I just wander is this some bug or I am not paying attention on some basic setup which is necessary for the high res render.

Without looking at scene and some of the settings no one really can help …

SreckoM
Without looking at scene and some of the settings no one really can help …

Well, ok, you are right.
So here is the scene. It is a box, mantra_ipr render (I just clicked render in the Render View)
the same setup with 1080 HD camera takes 6 seconds to render and the 2160 HD takes 0:07:09 which is 71.5 times longer.
I have an indie licence, so it can be due to that, or it is a bug, or I have no idea why would simply doubling resolution size result in 71.5 times longer rendering time.

EDIT:
I tried the same setup on the Mac machine, and surprisingly, everything works fine. So, now I am starting to think something is wrong with my windows machine. Should I RFE this?

Make sure you are not comparing in a renderview in preview mode, as the elapsed time for a preview render is meaningless.

jsmack
Make sure you are not comparing in a renderview in preview mode, as the elapsed time for a preview render is meaningless.

Ok, that's it, thanks I rendered to disk and it took only 30 sec.

If you uncheck the preview icon in your renderview then it will render at normal speed.
For some reason this slows down the render a lot on higher resolutions.