Ram usage

[tricky]

Increasingly, I am becoming aware of how much RAM our scenes are using, and trying to improve my knowledge on what to keep an eye on: geometry, lights, reflections, GI etc. With knowledge comes power!

I have a 'test' scene of a large office lobby. At the moment, it has around 1.7 million polygons. There are around a dozen simple ies spot lights, one vray sun and the vray sky.

When I render, the scene seems to use around 14GB memory - at least that is what the render dialog box tells me.

Firstly, is the render dialog box the place to observe the memory being used, or is there somewhere more accurate? I am not sure if each time I render, this value is being rest, or if it builds up during my current session of Max.

My render has 7 render elements, and I am rendering at 4000x4000.
These are the things I have tried to reduce the RAM:-

1) Disabling elements drops the ram by a couple of hundred MB, but nothing more.
2) Rendering to a vrimg (and just viewing the preview) makes very little difference
3) Switching off bitmaps globally makes no difference
4) Swithing off reflections globally makes no difference
5) Changing from LC/IRmap to LC/BF makes no difference
6) Turning off GI entirely makes no difference
7) Turning all lights off makes no difference
Dynamic memory limit set to either 4000 (the default) or 0MB makes no difference

I guess I've run out of things to try. Either the reported RAM usage in the render dialogue box is not the correct place to look, or there is some other consideration to make to reduce ram usage.

Any tips or suggestions would be appreciated to further my understanding of this.

[Morne]

Hi Richard

Things may have changed over the last few years, but I remember couple of years ago it was mentioned the Ram usage display in Max during render wasnt accurate. From there I started using Task Manager to check ram instead.

Also, and this is use at own risk, save your render before a render, then stick this into the listener:

FreeSceneBitmaps()

and then after that:

gc light:true

Let me know how that works for you (remember to press ENTER after each line)

It shouldnt be a DRAMATIC OH WOW, but hey, every little bit helps

[tricky]

Hi Richard

Things may have changed over the last few years, but I remember couple of years ago it was mentioned the Ram usage display in Max during render wasnt accurate. From there I started using Task Manager to check ram instead.

Also, and this is use at own risk, save your render before a render, then stick this into the listener:

FreeSceneBitmaps()

and then after that:

gc light:true

Let me know how that works for you (remember to press ENTER after each line)

It shouldnt be a DRAMATIC OH WOW, but hey, every little bit helps

Thanks Morné I will give that a try

[AlexP]

For such a small scene that it is a lot of Ram usage
Any VrayFur? Forest ?

[zeronove]

is 3.5 beta or 3.4 stable?

[tricky]

For such a small scene that it is a lot of Ram usage
Any VrayFur? Forest ?

No fur.1 forest object. Nothing complex really.

[vlado]

What's the difference between RAM usage of your scene before the render and during the render? The V-Ray log has various messages about RAM usage for different components, although they are scattered around and not in one place. Can you attach the log here?

Best regards,
Vlado

[tricky]

What's the difference between RAM usage of your scene before the render and during the render? The V-Ray log has various messages about RAM usage for different components, although they are scattered around and not in one place. Can you attach the log here?

Best regards,
Vlado

I'll take a look and come back to you

[eligiusz]

14GB is low, my scenes use 48 Main reasons are geometry or dynamic geometry and big textures. You didnt mention textures so I would look into that, do You use big resolution textures ? they take up a lot of ram.

[Morbid Angel]

14GB is low, my scenes use 48 Main reasons are geometry or dynamic geometry and big textures. You didnt mention textures so I would look into that, do You use big resolution textures ? they take up a lot of ram.

I also find that if you give windows more ram, it generally uses more, across the applications too. For example I have 128 gb of ram, and only maya / photoshop open and some how it uses 32 gb. This was never the case when I had a 16 gb system just 3-4 years ago.

But I actually think its a good thing. Perhaps before we were limited by the ram, so programs often had to take "shortcuts", by giving more ram, we can get more faster etc (this is obviously my assumption / observation).

[iancamarillo]

yeh i thought 128 was overkill for arch renders. I will never go back to 64