(Question) How to Utilize all 16 GB RAM with Vray?


#1

I have just upgraded my desktop RAM to 16GB (Twin 8GB) in a hope to achieve faster rendering time, im running on:
Processor I7-4790 3.6Ghz
Graphic Card 4GB Nvidia Geforce GTX 750 Ti
128GB SSD to speed up software usage.

after I did a test render with Vray, it only uses 4 GB Ram during rendering. Is there a way to utilize all RAM power available (16GB) To help Vray render faster?

I know that Rendering mainly use CPU power. but I wonder if there is a hidden setting in Vray to somehow make extra RAM more useful to aid render calculation?

another Question, if I want to use Vray RT (GPU) for production rendering, how many GB I should invest on my Graphic Card to be faster than my CPU Processor?

Any Answer is appreciated, Thank you


#2

For just an image
use primary- irradiance
secondary- lightcache
animation is a long explanation.
1.vray options/system/default geometry set to “static”-
2.set max tree depth higher …and test if scene is renders faster… if not leave it at default.
3.face/ level coef set smaller …try 0.5 …and test if scene is renders faster… if not leave it at default.
4-graphics gard get the maximum ram you can afford…Gpu rendering is way way faster than cpu.
5.Note a file on disk at 1gb will need usually 4x that to render on a gpu.


(Rob McPherson) #3

Make sure your dynamic memory limit isn’t too small. I usually set this by making a simple calculation which is ~ total ram minus ram used for loading the 3d model.


#4

@CPearase Thanks man, I have been using a set up just like u said for most architectural project. sometimes I switch to Brute Force to remove some splotches for many reflective scene. (just because it takes the same amount of time when I pump up IR Hsph Subdiv). I wonder if GPU RT will get faster result with my modest Graphic card.

regarding your point 5 “Note a file on disc at 1Gb will need usually 4x that to render on a GPU”, can u please explain it more?

@mcvltd Good Idea Man! thank you for that, I will try to set that to 12000 so that I still have 4 GB left for Application memory.
:slight_smile:


#5

@mcvltd The dynamic limit should be set taking into consideration the OS needs for RAM. There are lots of calculators online for that, for instance this: http://zdesigninfo.blogspot.pt/2012/10/vray-dynamic-memory-limit-calculation.html

@runnie If you are using win7 you can set your limit at 14400 Mb


(Rob McPherson) #6

Thanks Filipe, didn’t realise it was linked to OS like that and you don’t have to consider ram already used by Rhino. I’ll tweak my settings to suit!


#7

Im running on windoes 8, perhaps if I set the limit at 12000 Mb it would be safer ?


#8

@runnie I’m not sure about win8, but here is what I would do to determine the amount of memory your system is using. Open Windows Resource Monitor in the memory tab and shut all the programs you won’t be using during a render and Rhino. Look at the memory bar (the green part of it) and see how much is being used. Add a small margin and I believe you’ll be safe.

Note that if you set the default geometry to static, vray will use up all the memory it can regardless of what you set the dynamic limit to. The dynamic memory limit is only important for auto our dynamic default geometries.


VRay Using 99% of Physical Memeory (DIdn't happen in past)
#9

Thanks for the clear explanation!. finally I can maximize my Vray. Thanks all!


#10

Hi! Thanks for this thread, I am also in this moment of not being sure if my render is optimized. Basically I am not great with making very photorealistic renders so far with great details so now that a render with an empty room with a wood floor + windows takes 38 minutes, I am slightly worried about how it would be if I add various materials etc.

I am now trying to get a nice effective workflow for renders because I now feel it takes a bit too much time but of course, it is all relative. I have been rendering 300x300 images to get the light level right + displacement but when I got a proper lighting level, I just changed the resolution to 2000x1700 and all of a sudden the images were much brighter. So I am not sure I can continue like that.

I was trying to understand the settings etc, from what I understand the light cache uses 100 bounces as default while brute force only uses 3 by default, so instead of increasing the performance, according to the vray manual it should actually slow it down.

Anyways, now I am playing with the suggestions above but I am wondering if it is normal that it starts out “memory usage; 1.2 mb” when I have listed 800 mb as my memory limit? In task manager though it seems to use about 30% while the CPU is running at 100%. I also noticed my GPU had been unhinged /physically) while moving so I thought I found the issue of relatively slow renders but when I connected it, changed the cable to the GPU I do not notice a difference. Is there a setting for me to choose between GPU or CPU except for the RT engine?


#11

Info update for dynamic memory limit - set 0 and it is in auto mode and using all available memory. Sidenote: if the task manager shows a low RAM usage than V-Ray doesn’t need more.