Forcing an app to use one of THREE GPUs
 

Forcing an app to use one of THREE GPUs  

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jankymankey
(@jankymankey)
New Member

Firstly, I'm not quite sure this is the best place to post this, so if this isn't, I hope a mod sees it and can move it.

Secondly, I want to stress that this is NOT about selecting between a "power saving" and "high performance" gpu in driver settings or win10 settings. This automatically assumes the weakest gpu in the system is the "power saving" and the most powerful is the "high performance" and only let's you assign one or the other.

So getting into the full details:
I'm in a bit of a less usual situation where I'm using an eGPU (1080 Ti in an AKiTiO Node Pro), but my dGPU isn't that bad either (P5000). My system also has an iGPU (HD Graphics 630) which comes in handy sometimes. I've gotten all 3 of them operational on my system simultaneously but the problem is, when they're all active, (as I mentioned above) the HD Graphics 630 is treated as the power saving GPU and the 1080 Ti is treated as the high performance GPU by windows. This leaves me with no way to force an app to use the P5000, unless the app has that functionality built in (waifu2x-caffe for instance lets me select a GPU to process the image with, and I'm able to make it use the P5000). The big problem here is that I want to offload some apps from the 1080 Ti so its performance is less impacted, but I also don't want some of those apps to run like total sh!t (a web browser for example) if I disable the iGPU entirely from the bios, the P5000 becomes the "power saving" GPU which solves that issue, but now I can no longer use the iGPU at all. So, the question is, is there a way to force an app to use a specific GPU in Windows, beyond just selecting between the highest and lowest performing GPUs in the system?

Pending: Add my system information and expected eGPU configuration to my signature to give context to my posts

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Posted : Jan 29, 2019 9:26 am
OliverB
(@oliverb)
Noble Member

It's not by accident this system is called "Windows Hybrid Graphics" and not "Tribrid" or similar. So, no, you cannot do anything about it.

2018 15" MBP & 2015 13" MBP connected to RTX2080Ti GTX1080Ti GTX1080 Vega56 RX580 R9-290 GTX680

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Posted : Jan 29, 2019 10:51 am
jankymankey
(@jankymankey)
New Member

That's a rather limited way of looking at it. Obviously there isn't a one click gui solution for this, but that doesn't mean there's no way to do it. I've already shown its possible to use all 3 GPUs simultaneously (decoding a video with the iGPU, processing an image in waifu2x on the dGPU, and playing a game on the eGPU all at once). Windows itself can already choose between 2 of the 3 GPUs while 3 are active (as in the example in my first post), so obviously there's a native system for enumerating the 3 GPUs some way and allowing the selection of 2 of them. It doesn't seem a stretch to believe there is a way to take advantage of the extant system and extend that functionality to a 3rd GPU (not through the same GUI necessarily).

"It's called hybrid graphics for a reason" with no technical details or explanations of the limitation is hardly a satisfactory answer and comes off as condescending at best.

Addendum: from the Merriam-Webster Dictionary entry for hybrid as an adjective -- the second definition states, "having or produced by a combination of two or more distinct elements".

This post was modified 5 months ago

Pending: Add my system information and expected eGPU configuration to my signature to give context to my posts

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Posted : Jan 29, 2019 11:33 am
moobot liked