Dynamic Ram issue - negative not working

[Morne]

Hi all

So I tested this with commercial V-Ray 2.5 and with EDU V-Ray 3.00.07

When I type in a negative value, it jumps to 0.
When I set a negative value with maxscript, it jumps to 0, however when I check what the value is with maxscript it does show the correct negative value

BUT

It doesnt work as expected. You would expect to have that amount of free ram for the OS (-4000) in this case on 32GB machine.
But when the LC start, almost immediately it starts to "UNLOADING GEOMETRY".
However, when I set the limit to 28000, it happily calculates and renders without ever unloading geometry.

Is this negative function fully tested and supposed to work?
If not, please could you help me out with some maxscript that will check the total ram in the machine, so that I can manipulate that figure with some math

[jacksc02]

why on earth would you want to use a negative value?

[glorybound]

I'm not sure why you would want a negative number; I keep mine at 0. The Solid Rock calculates a %, which is also nice.

[Morne]

0 uses ALL available ram (or as much as the scene requires), leaving windows with nothing. This can lead to issues especially if you have slaves with less ram

a negative value is suppose to leave that amount of ram free (for windows or photoshop or whatever you want), and vray will use whatever is left

[svetlozar.draganov]

I've just run a quick test with version 3.00.08 and I can confirm that negative dyn mem limit set via the following command works:

renderers.current.system_raycaster_memLimit=-1000

Let me check the same thing for version 2.5

[Morne]

I've just run a quick test with version 3.00.08 and I can confirm that negative dyn mem limit set via the following command works:

renderers.current.system_raycaster_memLimit=-1000

Let me check the same thing for version 2.5

Yes that's what I said. Setting it with maxscript works, but then when you render it almost immediately starts unloading

[svetlozar.draganov]

It doesn't work for version 2.5

In your test how much was the occupied RAM with positive and negative dyn mem limit values?

[Morne]

It worked for me in 2.5 (setting the value, but rendering is dodgy)
I usually set it to -4000
Tested it on a 32gb pc and also a 16gb pc

[svetlozar.draganov]

By "dodgy" do you mean that the Unloading Memory process starts as soon as the render is started?

Can you run a few tests with the attached scene:
http://ftp.chaosgroup.com/support/dyn-mem-limit.max

It is a single plane with VrayDisplacement modifier. On my tests the Unloading Ram procedure only starts when Dynamic Memory limit is reached.
I have 16GB of ram on my machine, so with -5000 for dyn mem limit Vray starts unloading memory around 11GB.

[Morne]

Hi VRay Team

Is this fully working and implemented yet in the latest version? 3.20.03?
What I mean is can I now successfully use a NEGATIVE value in here for example -4000
So then if you had 32GB ram, instead of entering 28000, I can type -4000 and it will be the same thing? (If the user had 64GB, entering -4000 would mean a value of 60000)?

[svetlozar.draganov]

It works fine according to my tests although negative value cannot be set via UI only via maxscript.