Render Elements increase render times (a lot)

[Rick Eloy]

Sample rate looks just fine. Mostly blue (I'm controlling the Subdivs to make sure I'm not frying the sampler).

[svetlozar.draganov]

Try to disable all ExtraTex elements and see if they have the biggest impact on the render time.
If you could provide the scene for investigation we may find out why the rendering becomes so slower.

Another thing that is interesting to check is the memory usage, if the RAM is occupied up to 100% and windows start swapping information on the HDD they it is perfectly normal to have such slowdowns.

[Rick Eloy]

Thanks, Svetlozar!
The problem really lies on the AO (VRayDirt) bein on the render elements. As soon as I remove it, the render flies.
Funny thing is the rendering is not taking too much memory (it happens even with all materials overriden) and the VRayDirt map is pretty much default.
The scene is here for download if you're willing to take a look.
https://app.box.com/s/3nat99ildbub6u7dohw8xb10yuwhyvg9

[Zdravko.Keremidchiev]

I'm unable to download the scene. Would ti be possible to send us the scene to support@chaosgroup.com

[Dave_Wortley]

Didn't the subdivs for the VRayDirt get changed so you now don't need to have them so high? We have old renders with 64 subdivs that only need 8 now to get the same quality.

[Rick Eloy]

I'm unable to download the scene. Would ti be possible to send us the scene to support@chaosgroup.com

It's a bit heavy for e-mail, I'm afraid...

[Rick Eloy]

Didn't the subdivs for the VRayDirt get changed so you now don't need to have them so high? We have old renders with 64 subdivs that only need 8 now to get the same quality.

I usually set them to 32 at the most, so I don't think that's what's causing the problem... But I'll try decreasing it nonetheless.

[Rick Eloy]

Bingo!
Just left the default subdivs untouched (3) and it still looks nice and renders in a very acceptable time.
One would have thought this would be "disabled" like other subdivs on 3.3, but that's not the case (even though it works just like all the rest).
Thanks, Dave!