Computing sec. GI takes forever (low CPU usage)

[Tamyl]

Hi,
I'm struggling with this issue lately, probably after updating from Corona v3 to v4 (but I'm not 100% sure if that is when it started). I cannot render a scene, it stucks on the computing sec. GI stage, I'm waiting for 20 minutes and nothing is happening, CPU is doing nothing (about 3-5% usage), I have still over 10 GB RAM available.

My PC:
Intel Core i7-5820K
32GB RAM
Windows 8.1
3ds Max 2014 (x46)

[Frood]

You may check which process is using your W: drive so extensively (in resource monitor), you may get a clue there.


Good Luck

[maru]

I guess Windows is sometimes lying to us a bit about RAM usage and actually paging some stuff to HDD. Can you try optimizing this scene to lower its RAM usage and check if it persists, or see if the same happens in a new scene?

[PMVis]

I have had this exact issue with several scenes since updating to corona 4. What helped was setting 3ds max to high priority and checking conserve memory in the performance settings, although I am getting this issue with a new scene once again.

[Tamyl]

Thanks for the hints. This scene isn't that heavy and it is more or less optimized. I've just tested it on my 2nd PC and it renders without any issues and the RAM usage isn't that big (about 14 GB for 3dsmax.exe).
I've inspected the page file usage through the performance monitor in Windows and it really looks like there's something going on while the render is starting! It is weird for me, I have about 26 GB of RAM available on my main PC before I start 3ds max... Why is is happening, any ideas?

[maru]

Can you try disabling the page file, so that only RAM would be used? (just to test if it will help - this is probably not a very good idea for normal operation)

[PMVis]

I am having this exact same issue, that my D drive is at 100% during the calculating of the secondary gi phase. How do I disable the page file?

[romullus]

I think you're asking wrong question. If you'll disable page file, then most likely, max will crash. You should ask yourself, how you can simplify the scene, so it would fit into RAM. Alternatively you can try Corona 5 - it has some significant improvements in memory management.

[PMVis]

OK sure, but I am never getting a warning that my RAM is running low. The calculating time for secondary GI just varies so much, it goes from a couple of seconds to minutes with barely any changes being made to a scene. It's just hard to make sense of what is happening. Also how does the conserve memory setting work?

[Frood]

Has anyone having this problem meanwhile verified that it's in fact the system paging out stuff and not any other process torturing the disk maybe? :) Also it would be interesting to see the task manager details page of 3dsmax.exe with all memory related columns switched on when this happens.


Good Luck