Dual GFX cards expected performance increase?

[brobins]

Hey,

I have been running a single Quadro K6000 GFX card for a couple of years now and have been wanting to try adding another GFX card in to see how much quicker GPU rendering would be in VRay. On Firday I installed a 1080 ti as a second card and tested a few shots comparing render times.

It definitely performed quicker but not by much so I was just wondering if this is kind of normal?

To give you an example of times, one of the shots, which is an 8k render of a vehicles powertrain took as follows;

Quadro K6000 only = 42 minutes

Quadro K6000 + GeForce 1080 ti = 38 minutes

The next test I will do will be to only use the 1080 ti only.

I am not sure why but I kind of expected a larger increase in performance, maybe I am setting something up wrong?

Ben

[savage309]

The performance improvement should definitely be bigger.

Best,
Blago.

[brobins]

I thought as much.

Are there any specific settings that I should be looking for / checking? The purpose of me testing this second card is to determine if adding a second card warrants an upgrade, right now its not looking great

[savage309]

Some more info will be helpful:

* What host app is this?
* What OS?
* What V-Ray version?
* Are you using default settings or you have changed them? Screenshot of the settings will be nice to have.
* What kind of scene are you testing? Have you tried on other scenes?
* Do you have the V-Ray log?
* Have you monitored the GPU usage during rendering?

Best,
Blago.