CPU render only
GroveFast
Posts: 19
Hello,
I've rencently posted here regarding optimizing VRAM for my GTX 970 (4GB). I basically run out of RAM all of the time. SOme more experinece and now I clearly see my mistakes, and I'm back to only rendering 1 HD figure and a very basic HDRI map and a few props. No problems.
I want to render 2-3 HD characters + a decent sized set
Thinking about a 2070 8GB or just droping the money for a 2080Ti 11GB when hopefully the proce drops after the 3000 series introcuction
But I've also read other people suggesting that CPU render could be the way to go. So for the money of a 2080Ti, I can get a AMD Ryzen Threadripper 3960X Processor with 48 threads 3.8GHz (Boost 4.5GHz) for the same price as a 2080Ti, and then there is a much larger flexibility on the RAM, since updating that is cheap and easy.
I am wondering if anyone has any experience with CPU based render. If I have enough cores, will it be as good as a dedicated Graphics card? Is it just as cost effective, or maybe even better, now that AMD are relesing a crazy amount of cores for relative low prices. Would it feel the same during iRay mode in the viewport?
Daz 3D is part of 
Connect
DAZ Productions, Inc.
7533 S Center View Ct #4664
West Jordan, UT 84084
Licensing Agreement | Terms of Service | Privacy Policy | EULA
© 2025 Daz Productions Inc. All Rights Reserved.
Comments
I rendered this in 7 hours on CPU on an iMac with 8 cores, AMD Radeon R9 M395X 4096 MB. 6 full G8 characters with no optimization at all.
These guys give neutral reviews, and have been around for quite a while
https://www.youtube.com/watch?v=1LaKH5etJoE
https://www.youtube.com/watch?v=stM2CPF9YAY
Not quite what you were asking about but a I render using a GTX 960 one thing to try if you keep dropping to CPU only is to save the scene, close Daz Studio, relaunch DS reload the scene then render as DS tends to be something of a memory hog, especially if you have done test renders or even Iray previews, I have had many scenes that dropped to CPU which would then render with the GPU following this trick.
I literally just watched this video before checking back on the forums :) I mean literally!
The point was that if the workload (Daz in this case) is built for that many threads, it will work. So the questions then becomes, how mnay threads can Daz run at the same time in Windows? Would it be able to fully load all 48 threads on a Threadripper 3960X?
Yes I have noticed that as well. Restaring the PC even frees up memory, especially when using the graphics card to drive the display as well, which I do.
Wow nice render!
Yes this is my point actually. When just deciding on pure cpu render, you get so muchj more freedom to include what ever content you want. I find specifically the HD characters to hog alot of memory. I can still do 2 normal G8 characters and a scene, but as soon as I load an HD character I get the problems. I want to use HD character, becasue they look sooo much better (as in realistic).
Thanks for the nice comment. I am no expert by any means. Daz 4.12 did some remarkable nuts & bolts to my CPU renders and they seem to be going faster and smoother...I am a bit gob-smacked to be honest. There are much more tech savvy contributors here who will undoubetedly address your questions much better than I, but have you considered Scene Optimizer or Decimator to lessen the workload in the scene...or have I got this wrong, you would like many HD characters front and centre showing off their beautiful realism?
The problem is when loading only 2 HD characters in a scene, the 4 GB VRAM is basically spent. So if I have 2 or more characters close up in HD, my renders defaults to CPU. Now I have a i7-6700 running 8 threads 100% at 3.7GHz continious for hours. That renders at 1/3rd of my GTX970. So while CPU render is an option for me, it is a 3rd slower than running on the Grapgics card. When using both, I render decently fast. But it would be nice to: 1. have more VRAM and 2. Be able to have iRay turned on in the Viewport - especially when setting up lighting.
So I'm looking for a faster system. The idea I had was that maybe a CPU focused render machine with a S***ton of threads at high speed, could give me that scenario, and then totally forgetting about the Graphics card. So it is not a question of wether it is possible or not, but more is it economical now that AMD has pushed the multitread market so much. I mean even a 3600x gives you a lot of very fast threads for a very low price.
It could be interesting to see a direct comparrison between a 2080ti vs. Threadripper 3960X.
Thanks for the inputs, always good to discuss. I did some more seaching on benchmarks and found this thread:
https://www.daz3d.com/forums/discussion/comment/4762791/
That has the answers I need. Basically the answer is NO. A dedicated Graphics card is much faster than a cpu, even though it has loads of cores.
48 threads are not a problem for iRay. However the performance of a 3960 will be nowhere near the 2080ti.
2 to 3 characters, a set and a high res HDRI will fit on an 8Gb card much less an 11Gb.
I did a test of a single 2080ti versus a 1950. The TR was 6 times slower. So let's be generous and say a 3960X would only be slower by 2x. That might be worthwhile if you have no other choice.
But from looking at your scene, you've got a background and three different character set that don't interact with each other at all. Id Das Studio, you can render them separately and compose the results, can't you (canvases or something)? This is a case where the sum of the parts is much less than the whole.
Ye gotta have a ton of RAM for this on your PC, right? My computer would die just trying to load so many characters, not even talking about rendering. What are your render settings? Are you doing something to minimize load? I'd love to hear all your tips!
32 GB of RAM and I usually go for uncompressed textures and set the min and max to 8200. I also change the update interval to once every hour because I am in bed, so I don't need to see it update every 5 seconds - this is of course after I have done a quick render beforehand to see that everything is in place. Everything else I just ramp up to maximum so the render doesn't time out. Can't say I do anything too much out of the ordinary. I don't do anything to the scene to minimize the load.
If you want to use Iray, you need a GPU, no Threadripper can compete with that!
RTX are very good for Iray. The more VRAM you have, the better.
But keep in mind that the next GPU generation is on its way in some months, so I guess it's not the best time ever for this purchase!
...another trick to save a bit of system memory when rendering on the CPU is to switch the viewport to wireframe mode as the system no longer needs the overhead to display textures.
how much system ram you have?
32 gb RAM
Yeah, especially when the new models are released and the Turing cards are all dumped onto the 2nd hand market. Great time to buy a used Turing if a new Ampere isn't in the budget.
I'm having this issue since I downloaded the latest DAZ version a few days ago... my 12 gig Titan card never runs...I'm always on Cpu...
I've rebooted... I've unchecked CPU fallback... loaded a scene with only one cube primitive...
See my render results:
(see attachments)
JD
JD: Other people have been reporting this issue:
https://www.daz3d.com/forums/discussion/408226/please-can-someone-help-this-is-so-frustrating#latest
I would try out the latest beta version. I had this exact problem and upon switching to the beta, I now seem to have an easier time getting things to load into the GPU.
One thing to note, however, is that in your screenshot it looks like you're using task manager. My task manager won't register GPU usage when rendering because it's not looking for CUDA. The only way I can see the GPU use with Daz is by getting GPU-Z. Might want to check that out as your system could very well be using the GPU and you just can't see it.
Yeah.... no... when the render starts it clearly states CPU rendering...and it's slower...even with 10 cpu cores....
I did update my drivers... just now...and I was able to get the cube to use the GPU, but when I loaded a singel character with no clothes..it fell back to CPU,unless I removed the CPU as an option...
I will leave the CPU out of the pool for now and only turn it back on if a large scene won't fit on my Titan 12 GB...but I don't see this as an Improvement in DAZ performance....
Just saying...
JD
I've never been able to have both CPU and GPU checked off in the render settings...always had to use just GPU otherwise it would automatically drop to CPU. The exception is this most recent beta.