system optimization: rendering vs. creation

Discussions on this age-old topic often say “It all depends…” (on which is more important to you- fast creation (modelling etc.) or fast rendering).

That always frustrates me because it seems to beg the question somewhat.  One has to do both, and both halves seem to scale fairly equally (big complex models take longer to render).

I’m a green and want to reduce my power use, so i want to know: what does Blender (and most types of projects) tend to use more power at: creation or rendering, and by what margin (e.g. 20% creation, 80% rendering, or 50/50 or…)?

To rephrase: would i save more power with a fast(er) cpu or gpu system, or would a balanced system be as effective?

Infinice in Vancouver

There are two kinds of people: those that can extrapolate from incomplete data.  (you stop here, and wait- if the person is puzzled, you complete joke… “And those that can’t”).

In most general terms Creation would use less if you are modeling in a non rendered view port.

As soon as rendering occurs then power is increase as (either cpu or GPU) come under load processing it all.

Also when you Render you can turn off your monitor so you can save power there.

The biggest consideration should be the power efficiency of your Power Supply.

A more ‘powerful’ computer would use more power but render quicker.

A more ‘balanced’ computer less power but longer.

So you would need to calculate a Time/cost. Which then runs into what are you rendering? what settings etc.

So the best answer to being would be is you have solar panels/renewable energy. then only render during the times that energy is supplied.

Short of that you may possibly be able to find a ‘green’ render farm you can outsource your rendering too but the cost maybe high.

So to sum up. many numbers would need to be crunched but the one constant is get the most efficent powersupply you cant aka a Platinum rated PSU.

I hope this helps

I am Groot

I really do appreciate your efforts, and your remarks re PSU and solar panels are well taken (if a little obvious… sorry).

But most of what you said was just confusing. (e.g. “creation would use less if you model in a non-rendered viewport”).  

Maybe it’s my fault: perhaps i should’ve instead said, “what’s the least electricity use path: faster cpu or gpu?” to accomplish total task from modelling to rendering.


I’ve got a great new camera- it’s so advanced you don’t even need it. -Steve Wright

The least electricity use would be painting. 

Blenders viewport use is mainly drawing off of CPU usage so modeling/sculpting and such is mainly reliant on CPU. The GPU is mainly along just for the ride during this creation process. It is not until you get into using textures that the GPU gets involved then when it comes to the rendering process you have the option of using both CPU and GPU or just one of each. 

Which is why if your GPU is only a say 4 gig card you can still model and create a scene in blender and look at what it says the size of the file is. If it is over 4 gig you will typically be required to render out the scene on CPU providing you have enough system memory to cover the size of the scene.

All of that said a GPU will require more power consumption as well (larger power supply unit) vs a CPU only. But a GPU will help render your scene out in a quite shorter amount of time vs a CPU rendering.

In short if you are not worried about render times you could get away with just a high end cpu and system ram but if you are worried about power consumption then a possible render farm might be your better option. You will be able to ship it off and let someone else worry about power consumption.

Here is a link to a site as well that kind of breaks it down on how much power a pc actually uses.

What with the advent of Eevee’s drastically accelerating viewports, i conclude that the most efficient balance/compromise would be a budget cpu and the fastest gpu i can afford.  What do you think?

I appreciate the link too.  The render farm idea seems a pointless sidestep to me (paying for it instead of paying a higher power bill). And anyway, i’m a green, so passing the carbon footprint buck to somebody else, is no solution at all to me.


Skeleton walks into a bar, orders a beer and a mop.

The main thing that a lot of people don’t think about is that EEVEE is quick but that is because it cuts corners or actually more work involved in getting a photo realistic look vs cycles. They are two totally different rendering entities. Yes EEVEE is quick by default but once you start enabling everything then you will start to see it slowing down in the viewport. Also it is completely reliant on the GPU so depending on scene size then you may run into issues with a single GPU as that is all the ram that EEVEE will be using. Cycles will always produce more realistic results without having to adjust a bunch of settings to “Cheat” and get the similar result. 

That said if you are doing simpler non photo realistic renderings then EEVEE is just fine for quickness. So me personally I wouldn’t settle for just a budget cpu as you will still end up in a bottleneck. Plus there are some things that cycles does that EEVEE can not do.