Using a 2nd 'compute card' for KSP

[CalmLlama]

Hi,

Up until last year I would run two gaming computers, and the primary one I used for KSP was an FX CPU with dual 980s in it, and 32 gb ram.  A while back I switched over to my other computer (I7-6800k with a 1080), and I upgraded the ram to help with KSP.  I don't really notice a difference between running a single vs dual GPU.  I had been planning on buying a GPU to use as a compute card, but I'm not sure this would actually help.  Does anyone else use a compute card for KSP, will it actually help?  

 

 

 

[steve_v]

17 minutes ago, CalmLlama said:

I don't really notice a difference between running a single vs dual GPU.

Unsurprising, as KSP isn't particularly graphics intensive and SLI doesn't scale very well at the best of times anyway.

 

17 minutes ago, CalmLlama said:

I had been planning on buying a GPU to use as a compute card, but I'm not sure this would actually help.

It won't. KSP can't do anything with a compute card and the physics engine (AKA the reason KSP runs like crap with large part count vessels) runs entirely on the CPU.

Edited October 25, 2020 by steve_v

[CalmLlama]

4 hours ago, steve_v said:

Unsurprising, as KSP isn't particularly graphics intensive and SLI doesn't scale very well at the best of times anyway.

 

It won't. KSP can't do anything with a compute card and the physics engine (AKA the reason KSP runs like crap with large part count vessels) runs entirely on the CPU.

That's in line with what I've been seeing.  I keep thinking one of these updates will fix things... Thanks

[Incarnation of Chaos]

On 10/25/2020 at 8:14 PM, CalmLlama said:

That's in line with what I've been seeing.  I keep thinking one of these updates will fix things... Thanks

I was able to get some scaling by forcing CFX and tweaking the profile, but only with Astronomers visual enhancements installed. You need a GPU load before any additional GPU will get you anything, and KSP just doesn't have it stock.

Also as for the idea of using a Nividia GPU as a physx accelerator,  unity is using the physx library for physics but it's not running on the GPU. It's on the CPU, and heavily single-threaded at that.

So basically unless your computer is a "project car" already and you don't mind messing around with driver settings and profiles to brute-force modded graphics to acceptable levels of performance then there's no reason.