Internal NVIDIA graphics card with AMD eGPU

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Level 1

4 points

Internal NVIDIA graphics card with AMD eGPU

Hi!

I have a 2013 iMac with an NVIDIA GeForce GTX 780M 4GB graphics card. I've researched that this brand is no longer supported by the latest OS updates and that may be the reason why I can't use it for editing or CUDA acceleration??(I'm very new to this so please bare with me if that also isn't correct and if anyone can explain this that would be great as well). Question is, if I get an eGPU like an AMD one will this work with an already present NVIDIA card in my computer?

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Posted on Aug 27, 2020 4:08 AM

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Answer 1

Best reply

Jeff Donald

Level 6

15,938 points

Aug 27, 2020 4:55 AM in response to versia

An eGPU requires Thunderbolt 3. Your iMac does not support Thunderbolt 3. That is the only connection fastest enough for the graphics/video data. Here is Apple’s Support document on support and use of an eGPU,

https://support.apple.com/en-us/HT208544

If you need faster graphics than your 2013 iMac, your best bet will be the new 2020 iMac. As an alternative you could look into an Apple Refurbished iMac that has Thunderbolt 3.

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Answer 2

padams35

Level 4

3,343 points

Aug 27, 2020 6:58 AM in response to Jeff Donald

It's not that simple.

Thunderbolt 1: 10Gbps + 1x Display Port 1.1 channel

Thunderbolt 2: 20Gbps of combined data + video;

Max 1x Display Port 1.2 Channel
Max 16Gbps data (PCIe 2.0x4)

Thunderbolt 3: 40Gbps of combined data + video

Max 2x Display Port 1.2 Channels per bus
Max 32 Gbps data (PCIe 3.0x4) per bus
Min 10 Gbps data guaranteed available per port
Max 22 Gbps data (32 - 10) per port.

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Answer 3

versia Author

Level 1

4 points

Aug 27, 2020 2:31 PM in response to Jeff Donald

I tried that there is no option to select enable graphics card. I tried it in app it says there is no compatible GPU card found. But I've double checked and triple checked the compatibility of the card with Blender and on NVIDIA site and its listed as one of the compatible cards. Other forums have suggested work arounds but either I've tried them and failed or I'm not confident in messing with the SIP. I don't understand what the issue is when by all appearances this card should be in use : / The computer meets the minimum specs required and is actually in the range of recommended specs which would include the card if only it worked lol!

See spec requirements below:

Hardware Requirements

Minimum

64-bit dual core 2Ghz CPU with SSE2 support
4 GB RAM
1280×768 display
Mouse, trackpad or pen+tablet
Graphics card with 1 GB RAM, OpenGL 3.3
Less than 10 year old

Recommended

64-bit quad core CPU
16 GB RAM
Full HD display
Three button mouse or pen+tablet
Graphics card with 4 GB RAM

Optimal

64-bit eight core CPU
32 GB RAM
Full HD displays
Three button mouse and pen+tablet
Graphics card with +12 GB RAM

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Answer 4

JimmyCMPIT

Level 7

29,230 points

Aug 27, 2020 5:02 AM in response to versia

the eGPU could be used to drive an external display and work in conjunction with the 780

software for CUDA can be found here

https://www.nvidia.com/en-us/drivers/cuda/mac-driver-archive/

I'm on a 2013 4GB 780M from work, but I have a 2010 Pro with a stock ATI and a 1660ti running Windows 7 because I use CUDA for 3D work. Apple left Nvidia users in a lurch and support generally comes from Nvidia when they feel like it. The really sad part is so much 3D and AI work is leaning towards Nvidia right now.

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Answer 5

Aug 27, 2020 6:00 AM in response to versia

There is no official Apple support for any eGPU on anything

other than a Thunderbolt3 Mac.

Any solutions will be 3rd party or from the open source

community (read system hack) that should be done

at your own risk and note that any of the security updates

that will be available for the next two years could break everything.

To that end you can start here:

https://egpu.io

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Answer 6

padams35

Level 4

3,343 points

Aug 27, 2020 6:39 AM in response to versia

For editing try using OpenGL/Vulcan/Metal instead of CUDA if available.

For CUDA web drivers you have to downgrade back to High Sierra. (Also CUDA is Nvidea specific, so an AMD eGPU would not provide CUDA support).

Apple does not provide native Thunderbolt-1 eGPU support. Open source third party software can enable TB1 eGPUs, but TB1 has only half the data bandwidth of TB3 and will suffer significant bandwidth throttling that gets proportionally worse with faster cards. The 780M is fast enough that I would not recommend trying to improve upon it with a TB1 eGPU.

If you need faster graphics I'd suggest a newer computer.

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Answer 7

versia Author

Level 1

4 points

Aug 27, 2020 8:15 AM in response to versia

Thanks for all the helpful replies! Now I do understand that the best thing is to get a new computer. and that an eGPU wouldn't really work because I don't have that Thunderbolt 3 port. Cool. So I have a more specific question maybe. I'm using Blender which is an open sources 3d program. Now while I do have that Nvidia card in the system, Blender is not using the card. why not? I have tried to make Blender select the card for rendering instead of the CPU but its not an option. So barring getting a new computer is there anything I can do about this? I've downloaded the latest CUDA drivers and that didn't solve the issue. (I did this on the recommendation of someone else that it worked for). I also saw on Apple's site that I can connect an eGPU with an adapter to my iMac. So either I have Thunderbolt 3 to Thunderbolt 2 adapter or Thunderbolt 3 to USB connection. This probably still would not give me the full power of the eGPU but would it give me enough that I actually get to use a graphics card? Because right now I'm not able to use any. My processor is 3.5 GHz Quad-Core Intel Core i7. Not the latest or most powerful of course but if I can get that Nvidia card working along with the processor maybe I can get through Blender a little easier?

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