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GTX 1070 eGPU bottleneck with Macbook pro?


maarten

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Hello all,

 

I have an eGPU setup with an Akitio Thunder 2, and a late 2013 retina macbook pro with a i7 4850 HQ (2.3 Ghz). I recently put a GTX 980 into the setup, and I am getting decent speeds. I can run Battlefield 1 on 1440p / High at about 55fps. I am using it with an external monitor.

 

However, I saw online that this GPU should get about 68 fps at these settings. I know the eGPU setup bottlenecks the GPU somewhat, as has been shown by @Dschijn 's benchmarking.

 

So here is my question: What would happen if I put a GTX 1070 in it instead? Would it not improve performance that much, because the system is already bottlenecking with the eGPU? Or does the eGPU bottleneck just mean you lose about 10% performance vs a desktop, but the performance increase will still be there?

 

I also think the CPU might be holding me back at this point, so should I expect much performance increase in going with a GTX 1070 over a 980? Or is the CPU just going to hold me back too much. (I am going to try undervolting the CPU, since it reaches up to 95 degrees under load!)

 

Thanks for any insights!

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55vs68 FPS seems ok to me.

You run the setup with Thunderbolt, you have a CPU that will sweat a lot (BF1 is very CPU intense) and you have a high resolution.

A 1070 will give you better FPS, but I am not sure if it is worth it.

 

You should definetly try and help the CPU a bit.

Also DX12 could help with your CPU limiting.

 

Can you use a monitoring software? Maybe the GPU is not under 100% load?

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On 10/28/2016 at 11:46 AM, Dschijn said:

55vs68 FPS seems ok to me.

You run the setup with Thunderbolt, you have a CPU that will sweat a lot (BF1 is very CPU intense) and you have a high resolution.

A 1070 will give you better FPS, but I am not sure if it is worth it.

 

You should definetly try and help the CPU a bit.

Also DX12 could help with your CPU limiting.

 

Can you use a monitoring software? Maybe the GPU is not under 100% load?

 

Thanks for the feedback!

 

So I undervolted my cpu by 90 mV, and it does run a lot cooler now. (any lower than 90mV and it crashed) It went from reaching 100 degrees celcius and thermal throttling, to staying at around 88-90 max, and not throttling. So this should help with games as well, because I was getting framedrops when it overheated.

 

When running on High, in game the GPU is at 98% mostly, and the CPU is at 100%, I get 55fps

When running ultra. the CPU usage drops to about 60% or so, and GPU is at 100%. This gives me only 45 fps.

At medium, the CPU usage is 100$ and GPU is about 80%, and I still only get about 55fps.

 

Could this be because at Ultra settings the GPU only achieves about 45 fps, and the CPU doesn't need to work to 100% to keep up with that?

On the other hand, at medium, the GPU could probably output more, but the CPU is holding me back, still only getting 55 fps instead of 70 or so? It is weird that I don't get more Fps when dropping the settings. I this the CPU bottleneck then?

 

In that case, getting a GTX 1070 would not make sense, because I would probably not get any more fps?

 

I want to try DX12, but unfortunately the game crashes for me on DirectX12. This seems to be a pretty widespread issue.

 

 

Edited by maarten
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Seems like a classic CPU/GPU limit.

High setting will stress the CPU more because the GPU is so fast an waits for the GPU.

Ultra settings will stress the GPU to 100% and so the CPU will wait for the GPU to finish.

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