PC Graphics

[danthefatman09]

I have 2 Radeon VIIs installed in my Desktop Computer and am trying to see if it is possible to switch between them using the AMD Adrenalin software. I have followed instructions on other pages detailing out fresh driver installation, etc. to help but the option still doesn't show up. 

The purpose of doing this is that I am rendering animations and the Blender 2.8 Eevee engine will not use both Radeon VII GPUs at once, neither will it render on a specific GPU even when you select it from the menus- (including my attempt to use my Nvidia 1070 card instead of the Radeon VII if you can believe that...) it basically will only read the first OpenCL GPU on the list. I read that other artists with different Radeon GPUs have been able to render with specific GPUs enabled by changing the GPU setting within Adrenalin then opening up different instances.

Does anyone know if Radeon VII cards are switchable or know any possible way to solve the issue within Blender? I am quite stumped on this one...

[danthefatman09]

Hello all,

I have discovered a work around for this issue, specifically regarding the switching between the two AMD Radeon VII cards as the primary. I tried plugging my #1 monitor HDMI into my second Radeon VII Card and inside of Radeon Adrenalin, it switched the primary card to the second one. 

Since I am doing CMD prompt renderings with Blender, if I keep the #1 monitor HDMI plugged into my top GPU, set the render going, then switch the #1 monitor HDMI to the second GPU, then start another CMD prompt render, it will utilize both GPUs simultaneously since the CMD prompt is basically separate instancing of the Blender software.

I have not checked to see if the same will occur if I plug the HDMI into the GTX1070- will see later.

Although this workaround basically is doing what I would like, it would be ideal if I could simply switch the primary GPU within the Radeon Adrenalin software.

[tommorley]

I would bet that you can do the same thing by switching your primary monitor in the windows software. Start the first instance of Blender up then switch your primary screen in windows software to the second Radeon VII and start your second instance of blender. Let me know if it works because I bought one Radeon VII and am looking to get another one but will have the same issue. Have you tried Crossfire?

[danthefatman09]

I actually didn’t think to switch primary using windows. Not sure if that would work. At the time I was under a project deadline and had a minor melt down since I made a mistake on the render, costing me 12hrs if lost render time. I suppose I can try it out and see. Doing the renders with the separate instances after solving the issue took a 24 hour render down to 6 hours so I was really happy. 

To answer your other question- the crossfire doesn’t really work well in rendering altogether and with Eevee- there can be a bottleneck in the speed when running the render frame, composite then image saving (if that makes sense....). Rendering seperately instances seems to be better than cross firing. 

If you are thinking about getting a second Radeon VII, do it. I saw there is a sale for around $550 at some vendors. I have sound methods on using cmd prompt rendering using ProRender and each component seperately, not together, to reduce render times dramatically.

System: i9-9900K, 32 GB RAM, GTX1070, Radeon VII X2, Z390 Gaming Edge Plus, 1200Watt PSU, Corsair h150i pro cooler

I undervolt the VIIs, OC the 1070 and render 4 instances (cpu seperately) using CMD prompt (which reduces rendering time around %20-%30 per instance). For some reason it reduces the overall time a lot with my setup if they are done separately and undervolting the VIIs is around the same overall time as OC them, at least in my testing on some quick materials, and reduces power consumption by around 100 watts per card. Keep in mind- I have a very open case system and excellent cooling which keeps everything from overheating on long renders.

I can’t speak highly enough of the Radeon VII- it’s a fantastic card for the price and with the new drivers works very well, especially for compositing and editing 4K footage. I will say that the new RTX Optix rendering system is showing a lot of promise, albeit a little buggy and there are noticeable flaws in its calculations at the moment. I have the luxury of using and RTX 2070 in my day job capacity and the RVIIs on my workstation at home for my private clients. 

I know this is TLDR but I can’t sleep tonight so.... 

[tommorley]

Thank you for the extended information, it helps a great deal.

Yes, I picked up the Radeon VII for $550 and I'm really not a "pro" user but the card is insane for my workloads. I do blender work for my channel on youtube and nothing can touch this card at $550 with 16GB of ram. I run a lot of FOSS and OpenCL applications so this card is perfect for my needs. I got 3dCoat on sale and that runs amazingly well on the RVII as well. I wouldn't mind hearing any tips on the reduced render times. My YouTube link is below.

https://www.youtube.com/channel/UC7-x3X_xHkycGHLEIJtlkuw?view_as=subscriber 

[danthefatman09]

I subscribed to your channel. I am considering doing a couple tutorials at some point so I will keep you posted if that happens. 

[tommorley]

Thanks for the sub and guess what. Blender made it easy to render and pick the OpenGL render card. Check out how in this video.

Using multiple GPU to render an EEVEE animation in Blender - YouTube

[danthefatman09]

tommorley- I tried to select using the method you linked but it doesn't work... maybe becuase my version isn't through steam? dunno...