Issues with 2x 980ti

surody

I have 2 PCs, one has 2x 1080ti and the other one has 2x 980ti.
The 1080ti renders great, but when I try to render on my slightly older PC with the 980tis, every second frame turns out noisy in the same amount of time.
Of course I adjust the rendertime for each frame to compensate the power increase of the 1080ti, but like I mentioned, every second frame looks fine/bad.

For example:

I want to batch render 100 frames of a animation. 50 of those frames are fine but the other 50 are noisy (every second frame).

Does someone know the cause and how's that fixable?

JD_Mortal

Do the logs indicate that it is somehow cutting render-times short, or may be extending them oddly to other "limits".

Sounds like it is just resolving faster than it should, or maybe falling-back to an internal default render-setting.

Look at the number of iterations it reaches. That is the only factor for equality, related to noise between frames.

If, for some reason, it says it reached 100% resolve, or whatever setting you used... But if iterations reflect something like, 3000 then 250 then 3245 then 185 then 2840 then 312... etc... Then something is failing between frames. Could be a shader bugging-out, or a model may not be going into full detail... etc. (Something in-scene that would render faster, cutting it short of render-time, or extending it, so it can't resolve fast enough.)

A more specific example would be the following... (Requires a visual inspection of the output, to look for changes.)

1: Models hair or clothing not "conforming to the model", or "being decimated to a lower or higher level of detail".

2: Something "refractive", not rendering correctly, as if light is failing to pass-through, between frames. Such that it is spending more time trying to "figure out where the light is going", instead of rendering an actual resolved pixel.

3: Disco-ball reflections, changing angles, bringing more into the "frame of reflections", on every other angle/frame.

4: Depth obstructions, where items are dispearing behind other things, like in a city-scape. Making more appear between frames, to render.

surody

JD_Mortal said:

Do the logs indicate that it is somehow cutting render-times short, or may be extending them oddly to other "limits".

Sounds like it is just resolving faster than it should, or maybe falling-back to an internal default render-setting.

Look at the number of iterations it reaches. That is the only factor for equality, related to noise between frames.

If, for some reason, it says it reached 100% resolve, or whatever setting you used... But if iterations reflect something like, 3000 then 250 then 3245 then 185 then 2840 then 312... etc... Then something is failing between frames. Could be a shader bugging-out, or a model may not be going into full detail... etc. (Something in-scene that would render faster, cutting it short of render-time, or extending it, so it can't resolve fast enough.)

A more specific example would be the following... (Requires a visual inspection of the output, to look for changes.)

1: Models hair or clothing not "conforming to the model", or "being decimated to a lower or higher level of detail".

2: Something "refractive", not rendering correctly, as if light is failing to pass-through, between frames. Such that it is spending more time trying to "figure out where the light is going", instead of rendering an actual resolved pixel.

3: Disco-ball reflections, changing angles, bringing more into the "frame of reflections", on every other angle/frame.

4: Depth obstructions, where items are dispearing behind other things, like in a city-scape. Making more appear between frames, to render.

I figured it out. Apparently the 980tis are too weak for SubD 4 for the scene I used but the 1080tis aren't.

nicstt

Weak? Doesn't make sense.

I have a 980ti and have used Sub D 5; takes a little longer to process the scene; it might drop due to lack of RAM, but: No noise.

The only reason I can think of is that one of the cards is faulty, and perhaps both, which is less likely.