RAM or Processor bottleneck? - Rendering issue

[danielhagene]

I've been working on some heavy scenes lately, and they're just getting heavier and heavier. When I render it takes a while before "bulding acc." etc is complete, and alot of the times it totally freezes the computer or even crashes it. I can barely use my computer while I'm rendering, and I usually work in PS while I render - but not even my browser works while rendering.

The render "logg" says I need more ram, and that seemed likely as my RAM is at 90-100% during rendering, so is my processor (it's usaully at 90+ either way)

I've talked to the guy who built my PC, and I thought I needed more RAM, but he didn't - so he changed out my 32GB ram with some other 32GB ram-sticks (which he said was more stable). The new ram had zero effect on the problem, and he seems to be convinced that it's my processor that's at fault (not the lack of ram).

- the processor is Intel Core i7 5820K CPU 3,3Ghz

Anyone know which of the two is the main problem?

[Juraj]

Faulty ram doesn't manifest in hogging your performance, but downright crashing, your computer technician doesn't know jackshit and there is no such thing as "more stable" sticks....

If you use up to 90-100perc. ram during rendering, that indeed, you might benefit from more memory. 64GB memory is nothing unusual.

Than again, ever-growing scene has been 3dsMax staple issue for many years, always coming from different direction. There are multiple ways how to clean 3dsMax file.

Last, Corona displacement is heavy if you use it.

100perc. use of CPU is completely normal and not being able to use other processes especially when you also ran out of memory (browsing is quite memory intensive these days) is also normal. Do you use "low-thread" setting in Corona ? It should be ON by default.

[Nejc Kilar]

Usually when everything lags out (even the mouse) and your ram is in the 90%+ range then in my experience it is nothing but the RAM's fault.

Why? Well once you go over the threshold of available RAM then things start to get cached on your disk (instead of RAM) which is really noticeably slower for that kinda stuff. Having your pagefile on an SSD helps with that issue a lot but in my experience it can only take you so far since the computer can be operated but the precalc phase takes noticeably longer.

When rendering the CPU is usually above 90%+ on all the cores you have so that is rarely a problem. Things do slow down (for example, opening new pages in your browser gets really slow) but everything should be working.

edit: Juraj pretty much beat me to it. I did not say anything bad about the technician though :P

[Juraj]

edit: Juraj pretty much beat me to it. I did not say anything bad about the technician though :P

But these people are clueless yet we pay for them :- D

Giving you "stable" memory sticks (without running even memtest) and accusing CPU of being faulty ? What is this :- D ? Next question would probably be if you don't have virus..

[danielhagene]

Last, Corona displacement is heavy if you use it.

Do you use "low-thread" setting in Corona ? It should be ON by default.

I always turn off displacement on all objects. Tried doing it with the "low-thread" on & off - no noticeable difference.

[Juraj]

Do you less heavy scenes work fine ?

[Juraj]

Regarding scene file cleanup:

This is good script (do have backup before using) http://www.scriptspot.com/3ds-max/scripts/cleaner

To clean-up your memory occasionally you can use during your work: (type what is Bold into to lower-left script listener)

gc()        Garbage Collection.
freescenebitmaps()       Cleans up in texture memory.
clearUndoBuffer()        Removes your Undo's

[danielhagene]

Do you less heavy scenes work fine ?

Yes, Interior scenes works totally fine. But when i do exterior I have to first make the entire scene and then make individual MAX-files for each camera angle, where I delete things not seen by camera etc.. So it's not really that the scenes are too heavy too work with, it just too heavy for rendering.

[Nejc Kilar]

edit: Juraj pretty much beat me to it. I did not say anything bad about the technician though :P

But these people are clueless yet we pay for them :- D

Giving you "stable" memory sticks (without running even memtest) and accusing CPU of being faulty ? What is this :- D ? Next question would probably be if you don't have virus..

Forgive me as I never had a technician working with me / for me so I am a bit clueless as to what is actually happening in practice (and not in theory) :D Heard some funny stories from time to time although I did hear some good ones too where the tech saved the day!

[Juraj]

Quality technician who loves his job is heaven's blessing. I have a guy who built my Xeons and it's beautiful how he works. Extreme attention to details, great knowledge of every part on market available.

On other hand, you have these generic, good-for-nothings who probably took first job the public agency gave them, did 4-hour training, are lazy to learn anything about their job, don't have any deeper interest in the field and this is what you get...

Guess which one is rare (and owns his own business) and which one is commonly hired at hardware shops to help you out...

[Juraj]

Do you less heavy scenes work fine ?

Yes, Interior scenes works totally fine. But when i do exterior I have to first make the entire scene and then make individual MAX-files for each camera angle, where I delete things not seen by camera etc.. So it's not really that the scenes are too heavy too work with, it just too heavy for rendering.

Than you need to buy more memory or keep doing what you do (optimizing scenes manually). But there may still be some culprit and the scene can be unusually large to software or user error. You can send such scene to Maru/Corona guys to test if they have time.

[DarcTheo]

what kind of poly count are you working with in these scenes? with Corona i often find scenes eating up RAM rather quickly, especially if anything has displacement. Feel like i need 64gb sometimes instead of 32gb.

in regards to the RAM stablility comment....do they mean they gave you different speed of RAM? the speed of RAM with the mobo and cpu can change how 'stable' it is? i ordered a PC, they said it worked fine etc in testing but it kept crashing on me, they swapped the mobo because apparently the RAM speed wasnt great with that mobo, think it was ddr4 3000mhz with a gigabyte board. It works now with asus board...but then it could have just been a faulty mobo.

edit - just to be clear, I would probably agree that it is just optimisation of the scene or getting more RAM XD

[danielhagene]

what kind of poly count are you working with in these scenes? with Corona i often find scenes eating up RAM rather quickly, especially if anything has displacement. Feel like i need 64gb sometimes instead of 32gb.

in regards to the RAM stablility comment....do they mean they gave you different speed of RAM? the speed of RAM with the mobo and cpu can change how 'stable' it is? i ordered a PC, they said it worked fine etc in testing but it kept crashing on me, they swapped the mobo because apparently the RAM speed wasnt great with that mobo, think it was ddr4 3000mhz with a gigabyte board. It works now with asus board...but then it could have just been a faulty mobo.

edit - just to be clear, I would probably agree that it is just optimisation of the scene or getting more RAM XD

The entire scene is 50m polys, and I always turn off/remove displacement on everything. But when I optimise the scene it's way less polys/objects etc.. I'm not sure what he did with the RAM, other than that he switched them out for some other sticks (not really a computer parts kinda guy).

Ye, I'm beginning to suspect that I need 64GB of ram based on the responses here. Just want to be sure before I ask my boss to cash out for it :S

[Ricky Johnson]

Ye, I'm beginning to suspect that I need 64GB of ram based on the responses here. Just want to be sure before I ask my boss to cash out for it :S

I'd have said you could be fairly sure that's the solution. Your symptoms completely match what I've experienced when running out of RAM during the initial stages of a render or operating close to the limit.