Rays/s actual sooo low and render time soooo high :(((

[DRWZDC]

Hi all,
I am rendering a complex interior scene and it took already 24 hours to get 3-4 passes with very noisy and low quality (see attachments).

My specifications are:
- Mac Mini M1
- C4D R21
- Corona 5
- File Size ca. 1 GB

In previous projects I did not have so crazy problems. It is the first time.

I tried already that:
- cleaning up the scene in deleting all unnecessary objects and materials
- There are some complexer materials like the woodstamp concrete with displacements…or the rug…or 5 spotlights with an IES-Light. But can that be the problem?
- checking all portal light objects that they fit perfectly into the window holes
- using the default render settings with the GI/AA Balance
- Yes, I have a lot of lights there…also in the multi-pass lightMix Channel…should I reduce that to a minimum and/or use instances?

General questions:
- Could it be that Cinema R21 and Corona 5 are too "old" to do the job…and I should update it?
- Or/and are there mistakes I did so that it slowed down so massively?

I know that computers are only ever as intelligent as the person sitting in front of them! So please help me!! ;)))

Thanks!!
Best Doc

[Cinemike]

Are you possibly running out of free RAM?
Other than that, I suppose the support would need your scene to know more.

General questions:
- Could it be that Cinema R21 and Corona 5 are too "old" to do the job…and I should update it?

Corona 5 is not too old, but I still would use a recent version, because many bugs were fixed and they render faster due to many optimisations.
Give it a try, you can always go back, just in case.

CU
Michael

[bnji]

Hi,
There's a big chance that material or an object in your scene is causing a high consumption of RAM.
Are you getting the "Running out of RAM" message?
Could you please let us know how much-installed RAM is in your mac mini?
It would be handy if you can share the scene with us.
You can use our private uploader here: https://corona-renderer.com/upload
Let me know the outcome.
Regards.

[DRWZDC]

Yes, I got that error message "Running out of RAM"…but I got it in earlier projects from time to time too and it never caused so much trouble like in that project now.
And yes, it could be a material or object that causes the trouble but I cant identify it.
I have no idea anymore – so I will send you the file via the private uploader for checking. Thanks!

[DRWZDC]

I got the maximum possible RAM installed in the Mac Mini M1: 16 GB.
This sounds low but because of the new M1-Chip the performance was normally very good.

[Nejc Kilar]

As soon as you start "Running out of RAM" what happens is that instead of reading scene data from RAM (which is super fast) Corona starts reading it from your SSD / HDD and both are orders of magnitude slower than your RAM. So any time your are running out of RAM it is expected that the rendering process will get slower - a lot slower if you have a lot of data that doesn't fit into your RAM.

So basically, your computer stores things it needs for fast processing in your RAM. If your RAM is full then all the applications need to search for that data on your SSD / HDD which as we've established is a lot slower. Think of it like feeding the CPU with data, if you can't feed it with enough data fast enough it won't help that it's the UBER MILLION CORES CPU as it'll be bottlenecked by having to fetch that data from hardware that's a lot slower. It literally won't be able to calculate at it's fullest potential because the data to calculate can't be delivered to it fast enough.

Your best remedy? Upgrade to more RAM if possible or try to optimize your scenes so that they fit into your RAM (smaller textures / HDRIs, less subdivided geometry etc...).

[DRWZDC]

Your best remedy? Upgrade to more RAM if possible or try to optimize your scenes so that they fit into your RAM (smaller textures / HDRIs, less subdivided geometry etc...).

Unfortunately I cannot upgrade the MacMini M1 in terms of RAM. I also tried to optimize the scene.
Well…I shared the scene with the private Uploader and hope that you guys find the mistake which causes the problem.

And if its "only" the RAM…what else can I do to get those Renderings out of the machine?
Should I use a Renderfarm?
Should I in general look for a better "Rendering-Machine"?

[BigAl3D]

I think the M1 strategy will serve Apple well, and I'm waiting for a pro model next year, but the M1 Mini is not up to the task of that type of rendering and I love using Macs (minus falling behind on speed over the years). You're running C4D via Rosetta 2 so it's being emulated which slows things down. You're using an old version of Corona which is slower. If you're already paying for Corona, why not update to v7? They have fixed a lot of things since v5. Many people use textures that are larger than they need. If there is a clock in the background for example, I've seen people use a 700 MB JPG for the face of the clock. Keeping in mind that clock only uses about 50x50 pixels of screen size. Corona will have to load that 700 MB file into RAM, then down-sample the image to 50x50 pixels since that's all that is required for the final image. This is true with ANY render engine by the way.

Open up the texture folder for that scene and sort by SIZE. See what you have lurking in there and see how large it's being used in the scene. You might be surprised

Is this project a paid client for you? I'd love to see the room to get a better feel.

[DRWZDC]

If you're already paying for Corona, why not update to v7?

Yes, I updated to Corona 7 yesterday but still the render process stays looooooong – tooooooooo long with that scene.

Open up the texture folder for that scene and sort by SIZE. See what you have lurking in there and see how large it's being used in the scene. You might be surprised

I also did that but unfortunately wasnt surprised at all. ;) Only the concrete woodstamp texture is quite big (100MB) but is also an important and main material in the scene. But still, maybe I should size it a bit down.

Is this project a paid client for you? I'd love to see the room to get a better feel.

Yes it is. But because of privacy reasons I cannot yet post it here. It is a beautiful interior for a beautiful villa in switzerland.

It would be handy if you can share the scene with us.
You can use our private uploader here: https://corona-renderer.com/upload
Let me know the outcome.

I uploaded the file in C4D R21 and Corona 7 inclusive the textures of course. So I am very curious what the Corona-Team will find.
Me too, I will check the scene for some crazy geometry and materials…hopefully we will get a result so I can render the images out.

By the way, has anybody suggestions about a HP Workstation to use for the renderjobs instead of the Mac Mini M1 what can do the layout but not the renderjob.
What specifications are the best for cost effectiveness?

Thanks!!

[BigAl3D]

Yeah, I'm curious too what they will find.

On the Mac issue, we just added a loaded Mac Mini in one work station. Mostly for video editing, but I tested it to see how well it rendered with C4D to see if it's worth it to use as a render client. I always use the Grapes.c4d scene in the content browser as a real-world benchmark. The Mini is slightly faster than the old Trashcan™ to give you an idea. It rendered that scene in a little over 8 min. The iMac Pro I'm using right now, cranks out that scene in 3:19. Of course C4D is running natively on the iMac Pro and under Rosetta on the Mini.

Can't argue with going with PC and Threadripper CPU. Those things are blazing fast. Expensive, but time is money right? Good luck.

[bnji]

Hi there,
Thank you for uploading the scene file.
Could you please let me know the file's name to locate it?
Regards.

[DRWZDC]

Hi bnji,
the name of the scene file is:
DRWZDC_Scene Check_Corona7_plus TEX.zip

It is the C4D R21 file and the TEX folder.
Thanks a lot for checking!

[Cinemike]

I don't think it's crazy geometry, just too much of sane one :)

[DRWZDC]

I don't think it's crazy geometry, just too much of sane one :)

Hahahahaha…thank you very much, I'm sure, it is exactly that!! I hope! ;))

[DRWZDC]

Hi bnji,
did you find anything?

Could you read the file properly? I just saw that I did't integrate two IES-Lights with the TEX-Folder.
I could also re-upload the file the right way: "save project with assets"?!

Thanks!

[DRWZDC]

UPDATE: after cleaning up the scene in simplyfying some geometry and change some light material, still the rendertime didn’t change at all. It stayed sooooo slow, close to nothingness.

But then I had an idea: Don’t use the VFB renderwindow (what the normal way should be), but use the interactive renderer to see if the scene would act differently…and YES -> it is rendering the passes…!! I couldn’t believe! I used the same render settings like I used before with the VFB…so what is this?

ca. 19 hours of rendertime = 92 passes = 3,69% Noise Level
Rays/s total = ~110.000
Rays/s actual = ~25.000

I mean still it is quite slow (it’s a Mac Mini M1) but at least it is rendering.
Unfortunately I cannot do anything else because the program is blocked with the interactive rendering. And I also don’t dare to click anything because then it would start again from the beginning…ahhhh

So please - what kind of bug is that? Can anybody conclude? Did anybody experienced something similar? How can I fix that?

Thanks! Doc

[bnji]

Hi there,
I've been testing your file, and here are my findings:
-The intensive RAM consumption is due to a huge amount of objects in your scene file.
-Although you have 14+ million polygons, which is a kind of decent amount of polygons, it will be too much for your Mac Mini.
-Rendering scene consumes around 23GB of RAM + OS + Host app + Scene file loading. You'll need more than 32GB of RAM.
-I can also see that all of your Cloner objects are set to work in "Instance" mode instead of "Render Instance." Try always to set your Cloner objects to work in "Render Instance" mode. (except if you're cloning Corona lights)
-You can also try using Corona Proxy objects to improve your workflow and the viewport's performance.
I'll suggest first installing additional RAM if possible (it will depend on your Mac Mini's expansion possibilities.
Then, you can start optimizing your scene file by changing your Cloners' Instancing mode.
You may also want to optimize the objects' geometry to try to reduce the number of objects in your scene file. (more objects in your scene file will slow down the overall performance of the viewport).
I hope this helps.
Regards.

[DRWZDC]

Hi bnji,
thanks for testing and your reply. I will try your recommendations on optimizing the scene file.

Unfortunately I cannot upgrade the Mac Mini M1 regarding RAM – it is stuck with 16GB.
Well…it looks like a new render workstation is needed…and definitely it will be no Apple. ;))))

Regarding RAM…128GB is of course better than 64GB…but are there any restrictions or constraints concerning Corona Renderer or Cinema4D?
Has anybody good suggestions or is here in the forum a post which shows the best current PC workstation configurations? (price-performance-winner)

[bnji]

Hi there...
You can find some interesting posts here: https://forum.corona-renderer.com/index.php?board=32.0
(regarding hardware performance)
I hope it helps.
Regards.

[BigAl3D]

I mean for a serious interior with lots of complexity and a huge number of passes, you're asking just too much from that M1 Mini. I love Macs too, but that's just not something I would try. I am running a 2017 iMac Pro and it holds its own with rendering. In my personal test, rendering the Grapes scene from the content browser, the M1 Mini 16GB renders (8 min) that scene a bit faster than a loaded trashcan Mac Pro 18-core (8.5 min). The iMac Pro renders that scene a lot faster. Somewhere around 3.19 min. Half the time. I think I already mentioned this.

I know a Threadripper CPU will blow mine away, but you will also need to drop serious cash on it. Threadripper Pro 3995WX, 64 cores / 128, $5,489. That's just the CPU. So you have to decide how much your time is worth vs what you can charge your clients. You might find that within a few months, you can earn enough from paid work to pay that beast off. In that case, it's a no-brainer. Drop 8 or 9 thousand dollars on your workhorse. Makes sense.

I will also add that you need to learn what are the minimum settings that you need for Corona to produce the quality your clients need. I know you can't share the image you are working on, but make sure not to overdue the quality settings. There is a point of where the additional passes won't really increase the quality of the image, at least to the human eye. This also leads into the question which you should always ask a client "What is the final image being used for?" For example, if you're rendered image will be printed on a large banner or billboard to viewed from far away, you can get away with very small render sizes. Not only the size of the image, but the number of passes too. Many types of printing processes, such as inkejets, can mask many of the artifacts you may see up close. I also recommend finding out the final vendor that will use your image and asking them directly about the specs for your image. Best way to learn.

A full page ad for Architectural Digest using 150 line screen for images, you need to crank up the passes. Sorry for the rambling post, but my mind won't stop.