GI precomp stage is very long

[lancer_91]

Hello guys,
I'm a newbie in here and getting a issue in rendering.
Here is the issue picture

My rendering is taking with GI computing lasts forever. In the scene, I use many corona scatters to make grass and trees. All plant models is from evermotion models.
I also notice rays/s is very low. Rays/s is often over 1000 for my previous scenes. But now it is very low. I heard that too many opacity maps would increase render time significantly.
So I really need help in here.
Thank you so much.

[lolec]

Definitely upgrade to 1.6   99% chance it will fix your issue.

[lancer_91]

i don't know how but when I choose every single tree proxy and disable animation, the problem looks go away.

[FrostKiwi]

i don't know how but when I choose every single tree proxy and disable animation, the problem looks go away.

114777 mio polygons. That is quite the feat.
Obviously it is smart to update, like lolec said, but can you check RAM usage? Maybe it started paging to the HDD and thus killed the speed.

[Ludvik Koutny]

There's a fair chance you've just ran out of RAM and Windows started to swap memory to the disk :)

Given the resolution of the screenshot you've posted, I assume you are working on some low to mid-end laptop. So my guess would be your machine indeed doesn't have much RAM to begin with.

[Ondra]

There's a fair chance you've just ran out of RAM and Windows started to swap memory to the disk :)

Given the resolution of the screenshot you've posted, I assume you are working on some low to mid-end laptop. So my guess would be your machine indeed doesn't have much RAM to begin with.

But Corona shows a warning about running out of RAM, that tells the user that he might experience slow rendering because of that. So running out of RAM is not possible, unless OP specifically ignored it...

[maru]

I would also bet on running out of RAM.
Anyway it looks like you are rendering an exterior scene, so using PT+PT might make more sense.

[lancer_91]

Hi guys,
My rig is I7 4790k but ram is just 8GB. And maybe that's the problem. While I was rendering the scene, I also ran AutoCAD to fight with my deadline :D
And when I bring the file to my rig at home (FX8350- 16GB ram) and leave it for rendering, the rendering process took very fast.
I'm really a newbie in here.
Thank you for all your reply.