First frame renders twice as fast.

[wafflelad]

So, I don't know if this is normal or not, but I wanted to make sure I'm not missing out on some more render speed. Whenever I send an animation to render, the first frame will render roughly twice as fast as all of the frames that follow. For example, on my current project the first frame will render at 12ms/sec and take about 1.5 minutes to finish and the rest of the frames will render at about 5ms/sec and take about 3:30 to finish. Why would the first frame go so much faster? Also, it doesn't matter where in the animation I start the render, so it's not a matter of a particular frame being quicker to render. It's just whatever frame renders first.

Joey

System:
Mac Pro 4,1 with single 780ti
C4D R17 / Octane 3

[aoktar]

I have heard that first time. Expected result is reverse of this.

[wafflelad]

That's exactly what I would think. It's a little frustrating thinking that potentially i could be rendering these frames at 12ms/sec instead of 5. Especially since I'm on a deadline with this render.

I guess I'll ask this in a more general forum in case anyone not using C4D has experienced it.

[aoktar]

Nobody will help in standalone topic about c4d related thing. Also i can't help without seeing any scene. Only thing which comes to mind is that you have much more VRAM usage on next frames and somethings run from SYSTEM RAM and makes slowness.

[wafflelad]

Ok, well here's the scene if you want to take a look...

Thanks.

[aoktar]

I have deleted your link. I'm gonna check thanks!
What the range? from 0 to 1000 or so?

[aoktar]

After checking and rendering it this what i got. Can't see any issues here see image. You can try to change render method to "manual assignment" if helps.

[wafflelad]

Hmm. I tried "manual assignment" but it didn't make any difference. It actually looks like it might be a little slower.

Could it be an issue with my GPU throttling itself? I wouldn't think there should be any cooling issues with the one card in my Mac Pro. I'm powering it with an external PSU, as well, so there's nothing weird going on with the power supply.

[aoktar]

Possible. Can you check different frames on LV? It seems stable on me with this way also.

[wafflelad]

Live viewer at full screen (1680x1050) renders at about 9.5ms/sec. So, almost as fast as the first frame render speed. I checked a variety of frames and some render a little slower, but always faster than the picture viewer speed. It is a slightly lower resolution, though. When I get time, I'm going to try a brand new scene and see if the problem persists.