Eevee slowed by 90% or more

Your patience with the noob is much appreciated. When I started with Blender a few months ago, I challenged myself to render a nice watch animation. It was my first animation render, so I had no idea how long it should take. The link is at the end of my rambling. It took about 2 or 3 seconds per frame to render. That was Blender 2.83. Now I’m up to 2.92. Eevee seemed really slow, so I went back to my old watch and re-rendered that animation. Now it takes over TEN TIMES as long. Same settings. 2020 iMac, 72GB of RAM (Photoshop guy by trade) I have gone back to 2.83 and it takes even longer to render now. I’m beyond confused. Throwing myself on your mercy. Here’s the animation:

What is your GPU? You watch with an external vRAM monitor app the vRAM usage of the GPU. When Eevee falls out of memory, render times are greatly increased.
There are many reasons why you may be using more vRAM now than before, for example your OS using more vRAM for some reason. Or now trying to render at a higher resolution than before (The higher the output resolution in the render, the more vRAM is necessary)

But to find out more about what exactly the problem might be, you should share with us a .blend file where you have problems.

Thanks much for your expertise! GPU is AMD Radeon Pro 5300 4 GB. I’ve tried switching to CPU, to no avail. Cycles shows me memory usage in real time. Eevee doesn’t. Strangely, Eevee is now no faster than Cycles. It was exponentially faster before. Let’s see if I can find that file… DOH, I found it but can’t upload because I am a new user : ( I’ll see if I can put it elsewhere and link. OK let’s try this:

Hey so part of the issue is that eevee is 100% gpu based and works best with nvidia gpus. Amd gpu will work but has had some driver issues so that could be part of the issue. But overall it also could be the mac os has a bug or something.

Thank you! I will look into both OS and AMD issues.

Eevee uses OpenGL, it always uses GPU, it is not necessary to configure anything extra. Always it is necessary to monitor vRAM usage with an external app because Blender with Cycles shows an inaccurate vRAM usage information. But apparently it is not a vRAM problem.
Have you enabled Depth of Field in Camera before for that video? Disable it and you see if you have reasonable times again.

Thanks much, will try all that… Checking in and out, CRAZY day, not even kidding, mad gunman loose in my neighborhood, helicopters overhead… Sheesh. Hard to think about drivers.

Yes depth of field was huge. Thank you. And your English is excellent.

Sigh. Downloaded the Radeon Render engine for Blender, which faithfully crashes Blender…

Still working on it… Downloaded Radeon Render engine, not good. Crashes every time. Sigh… Obviously there is an issue between the GPU and Blender, and between the chair and the keyboard…

Slow down, being a noob and being in a hurry is not a good combo. I’ll take a look at your file, my guess is some incorrect render setting you’re overlooking.

Thank you. I needed that reminder… I was able to get back to reasonable render times with my noob watch file, but I have other files now causing issues. I think it’s my geo, subsurfs, materials with lots of nodes… I need to learn more before I bother you experts! Something is making my Blender all crashy and slow… That’s a very general problem… Appreciate your time : )

Ok…so my render times are as expected, around 3 seconds per frame. I think there is something off with your actual camera/cameras since when I look through them I can’t actually see anything.

Also, you have a lot of geometry for a relatively simple object, over 2M tris. For instance, for the armband you can simplify that considerably by using reference copies or instances instead of actual geo for each and every piece of metal. Conversely you don’t seem to have enough geometry where it would actually count such as the watch body.

Nonetheless, I think something else is happening which is not related to EEVEE, granted I have a GPU with twice the RAM and considerably more powerful than what you’re using, but you should still be able to get reasonable render times (i.e. within 10 seconds per frame).


Start with the doughnut. I know it’s stupid and I guess David Price is getting on a lot of people’s shortlist lately, but I think it’s an excellent series that teaches a lot about how to properly set up elements in Blender and get decent render times.

Also, forget Radeon ProRender, it’s dumb and doesn’t work half of the time. Stick with Cycles or EEVEE which both work great in OS X.

Lastly, stick with official Blender releases. 2.92 is still beta, not a good idea. Use 2.91.2 which just came out the other day and you will at least remove some variables from the troubleshooting.

Not an expert here, and you don’t bother anyone either.
Just open a new thread for each new problem you have, and describe the problem you are having as well as possible. Much better if you share the problematic .blend file so other users can analyze it.

Thanks so much… So I learned something today. 1. My files are a little sloppy. 2. Blender has never even seen my GPU. I can’t seem to make it see my GPU. I went back to 2.83, where cycles render devices show up in the system tab of preferences even if it doesn’t see your GPU. It says I don’t have a GPU. But I do have a new GPU… It doesn’t like my AMD perhaps. Or my Mac. Or my OS. Might be stuck with external GPU or CPU… I did get 3 second frames with my watch as long as depth of field is off…

Apple discontinued support for OpenCL and CUDA in favor of its own technologies. So MacOS users cannot use GPU computation for Cycles in Blender. MacOS users can install Windows or Linux in dual boot in order to use GPU computing in Cycles.

I’m not sure if I understood. You check that “Cycles Render Engine” is enabled in Edit > Preferences > Add-ons. In some version of Blender there was a bug where Cycles was disabled.

I am not sure I understand what is actually happening. When you say Blender can’t see your GPU, what do you mean exactly?

What OS X are you running?

Understand that your experience is atypical for a Mac user, normally Blender runs just fine in OS X, and EEVEE is quite fast, although Cycles is only reliant on CPU computation, it does leverage the excellent Intel noise reduction.

Hi Again, and thanks again… Blender actually runs fine, it just seemed to slow appreciably while rendering. Part of that was settings, which I’ve remedied.

When I say it can’t see my GPU, I mean it doesn’t recognize my GPU as a Cycles device.

I am able to get 3 seconds per frame on the watch in Eevee, even without my GPU getting involved. The weird thing is that when Cycles is rendering, my GPU fan comes on, which tells me it’s working. When Eevee renders, the fan does NOT come on… I believe my noob geometry and materials are partially to blame, but it doesn’t make sense that Blender can’t see my GPU but still triggers the fan.

I can still use Blender, I just need to be realistic about render times I think. I came to Blender as a Photoshop guy for a few decades, so I didn’t know what to really expect in that regard. I’ve just upgraded my Mac to the latest OS, BIg Sur. It didn’t change anything with regard to Blender performance.

Agreed on the Radeon ProRender… Same goes for Luxecore. I’m sticking with Cycles and Eevee and learning to get the most out of them. Thank you for your help! I can return the favor if you ever get stuck in Photoshop.