Rendering times

[glorybound]

Yeah, something isn't right and I do not think it is V-Ray. All of my exteriors render in about an hour, and they are large, and I am on a laptop. I use progressive with denoiser at around .4

[seandunderdale]

unless you're rendering IMAX Avatar images, a single render should not take 70hrs+. Definitely a workflow issue.

[Vizioen]

Look, as I already said a couple of posts ago. This thread is useless without any information about the scene itself (interior/exterior, amount of polygons, amount/type of lights, types of materials, settings used). So unless you want to share some information on that, I see absolutely no point in posting every couple of weeks that you have a scene that renders painfully slow.

Venting or ranting about rendering times has no value if either the devs or your fellow users don't know what can be done to improve your rendering times. You can actually package the scene, send it over to them for investigation and they'll be happy to help, and there wouldn't be a problem with NDAs either. You might have even discovered a bug or something that can use optimising.

If you're rendering an interior with lots of lights and lots of reflective and/or refractive materials, then yes it can render quite slow, but these scenes can be optimised to render somewhat faster with the use of some "clever" tricks.

[JuhaHo]

All the materials ore slightly modified built-in V-Ray material library materials Steel Blurry being the most common There's no transparent materials in the scene. The light is based on 8K HDR Dome. I know it would be much faster if I just gave up using the HDR dome for light and reflections, but then the metal surfaces would look quite dull.

My job is mostly industrial product visualizations and my default resolution is 300dpi A4 (3508x2480).

[JezUK]

Complete guessing here, but that sounds like a render that'd take me somewhere between 15mins to One hour tops (and that's being super generous on my part).

I don't know how you have the patience for 77.5 hour renders! (your quality must be suffering as well due to snail-like visual feedback).

My cpu is pretty old now (I think around 5 years, so I always use my 2 x GPUs to render these days).

Your electricity bill must be pretty huge too

[glorybound]

I would send it to Chaos cloud and see what happens. If it renders in 5 minutes, you know it is your PC.

[JuhaHo]

I have one idea. Maybe it's the power. I'm on laptop and using my traveling power. When connected, the laptop says, for full capacity, You need bigger power supply. After all, I have noticed, the fan of the laptop is running seldom while working away from office. I would have a spare 200 W power supply from my old mobile workstation. However HP has changed the connector type and I have not yet found suitable adapter. Could it be that significant?

[Joelaff]

The task manager should show what speed (frequency) the processor is running.

If this is lower than the speed that processor is supposed to run, then yes, the processor is being throttled and not processing as fast as it could.

[trick]

After 3 pages of very little information to resolve this thing, I think it is wise to download the VRay Benchmark and see if your system is scoring somewhere near the already tested systems. There you can also see what exactly are the specs of your 8-core Xeons (of your dual xeon workstation), because there really are a lot of them!

https://www.chaos.com/vray/benchmark

Then there are 2 possibilities: your machine renders slower than expected...then it is failing hardware.
Or your machine renders as expected: then you have to start disecting your scene (deleting things) until it renders a lot faster. I even had scenes which render slow after completely deleting everything; so I would start with that. If that would be the case you would need to merge all the scene content in a new scene, either by doing a merge from the original scene, but better by save selected everything from the original scene and merging the saved into a new scene. There really are a lot of things you can do to test where the slowdown is coming from.

Either way, your rendertimes are not normal.

[JuhaHo]

I have tested my main workstation earlier and the results were on the faster side compared to other systems having similar processors. The speed results with my laptop were about 1/3 compared to the main workstation. I haven't yet tested my laptop with the travel power adapter. I don't know if the amount of RAM has any significance. Main workstation has 96 GB while laptop only 32 GB.

[Joelaff]

Easy enough to tell if the machine is running out of RAM by checking the Task Manager.

[trick]

I have tested my main workstation earlier and the results were on the faster side compared to other systems having similar processors. The speed results with my laptop were about 1/3 compared to the main workstation. I haven't yet tested my laptop with the travel power adapter. I don't know if the amount of RAM has any significance. Main workstation has 96 GB while laptop only 32 GB.

23hrs rendering on your dual workstation is still way too much. So start dissecting! I read in another thread that you needed "a few days" to import models. Do you have crazy amounts of objects/instances in your scene that are not optimized? Like zillions?

[JuhaHo]

The task manager should show what speed (frequency) the processor is running.

If this is lower than the speed that processor is supposed to run, then yes, the processor is being throttled and not processing as fast as it could.

Your electricity bill must be pretty huge too

Thanks,

I checked this. It's running 2.11 GHz out of 2.9 GHz. So this partly explains it.

I think there's big difference if there are metal materials in the scene. If there's mostly painted materials, I have no rendering speed issues. After all, the clients are in process industry, so mainly acid resistant steel it is with only few painted parts out of thousands.

I don't worry my electric bills. They a included in my office rental as well as coffee and cleaning services. On the countryside where I'm working at the moment, we have solar power plant on the roof. Actually I'm selling electricity more than I'm buying. This time of year the power plant is down between 01.00 and 04.00 AM.

[seandunderdale]

Are you using super high res bump maps to create anisotropic effects? You say its mostly metals thats are the problem. No variation in CPU speed is going explain a 3k render being 72hrs. In my early days of working in CGI studios, I was told, "youre allowed 1hr per 1k of an image in render time". Thats not a hard and fast rule, but it meant if my 3k render was 6hrs or 12 hrs, I knew I had a problem with my setup. Unless youre rendering motion blurred liquid with SSS, and tiny high intensity lights with depth of field on, and displacement everywhere, with dispersion on...then your renders should be much much faster.

It sounds like you've chosen a brute force method to do a simple effect.