Iray fallback to CPU because of Ram?

hallo_ich_bins1815_74a34261fc

Hey everyone,

I experience sometimes a fallvack to CPU in Iray Renders. The Info Box says "Geometry memory consumption: 203.935 MiB (device 0), 0 B (host)". But the task manager shows, that I am running out of (regular) RAM, I know that there is a fallback, if you run out of VRam, but is there a fallback for running out of (regular) Ram too? So would some more Ram be a cheep fix to keep Iray going?

PC with 8GB Ram and a 960GTX. I plan to upgrage it when 7nm CPU and GPU is available.

Kind Reguards

Snuggins

I looked it up and the 960GTX has 2G of VRAM -- I think that's the kicker, you will want to upgrade the video card to one with 4 or preferably 8G of VRAM, before any of the other stuff kicks in where you need to worry about system RAM.

Though it probably has nothing to do with why you fall back to CPU I will still answer (or try) your actual question. Your system manages your RAM so that if you need more RAM than your computer has physically, it will use the hard disk (hopefully an SSD) to "swap" out programs that are not currently active to make room in RAM for whatever is asking for more RAM at the moment. Then lets say you need to check your email or look at Chrome-- it will load it into RAM and move the program you were just using to disk, or part of it. Bottom line is *this is incredibly frustrating and slow* and will remind you of using a computer 10 years ago and make you want to kick your computer. Because there will be lag, and you will click somewhere and nothing will happen, and then all the things you clicked will happen at once like a minute later and drive you nuts. I deal with this on a daily basis with my work computer and I hate it. But that's how the system deals with low RAM.  

To upgrade the RAM, you might be lucky and have an empty RAM slot on your motherboard and can just plunk in another 8G stick. But be careful it likely is not so simple. Be sure you know exactly what motherboard you have if it is a no-name, or what model of branded computer you have and call support for that brand or google the exact model number. Not all RAM is the same.

So I would think the priorities are: 1) new nvidia videocard with most VRAM you can afford.  2) stick another 8G in the system ram slot if you have it, or find out if you have an empty slot, how many slots there are, does it go in pairs, etc. Call suport. 3) Just get a new computer with everything new. Lots of people do (3) prematurely when you could upgrade but if time is of the essence and you don't like fiddling as a hobby and you have the cash, (3) is the way to go.

Mattymanx

If you are using a lot of instances, set instance potimization to Memory instead of Speed in the Iray render settings.  This will take up far less vram.  Textures will also take up a lot of space.  Either reduce their sizes or get rid of them.

I have a product that was designed to help reduce resource use for Iray - https://www.daz3d.com/resource-saver-shaders-collection-for-iray - At least look over the info in the promos.

 

areg5

2 gig of Vram isn't enough to do a decent scene.  One of my cards used to be a 708 Ti, and that had 3 gig.  Very tough to desgn a scene that small.  As soon as you put to figures in it, you're done.  You can try lowering the resolution of everything in the scene as much as possible, like with the Scene Optimizer.  Of course, if you lower it too much it won't look good.