Single vs DR render passes

[hrvojezg00]

Hi, I`ve wanted to ask this for a while now. When rendering an image to 3% noise, a single machine render takes around 60 passes in 6k resolution, but for a DR-rendered image with eight slaves, it takes more than 200 passes to reach 3% noise. This is not isolated case, it happens in all situations/3d environment. Is this a known fact?

Thanks,
Hrvoje

[TomG]

Coupla starter questions. How often are the machines set to communicate with each other? And are they all the same speed?

There is generally some overshoot possible, e.g. master machine is slower than the others (maybe because it's in use for other things at the same time, as well as hardware), so when it goes "Oh hey everybody, 3% noise, we got it!" the other machines go "Great! Ok we are stopping, and here are the last 20 passes I did since you last asked me", which across 7 machines would be an extra 140 passes. This can happen even if the controlling machine is not slower, again depends on how often they are set to checkin with each other.

What's the breakdown on how many passes came from which machines, btw?

[hrvojezg00]

Hi Tom, all nodes have the same hardware, except a dual CPU, but that one is never the master. We`ve set the sync interval to 90 sec. Everything lower messes the nodes when rendering 6k renders. Approx. each node does 1-2 passes in 90 seconds, so it`s not 20-30, which would result in a higher pass cumulative count after each sync interval. Nodes/master are separate from the day-to-day work and only render one render at a time. This is something that has been happening for a while now, and we use DR only when we are in a hurry to render 1-2 6k render due to this issue. It would be great to hear exp. for other forum members who use DR.

[hrvojezg00]

Here is a sample of this issue. DR at higher passes numbers has double the amount of noise compared to a single render.

[Avi]

Hi,

We would like to investigate this issue further.

Can you please send us a ticket along with your scene and some repro steps?

https://support.chaos.com/hc/en-us/requests/new

[hrvojezg00]

Hi,

We would like to investigate this issue further.

Can you please send us a ticket along with your scene and some repro steps?

https://support.chaos.com/hc/en-us/requests/new

Hi, just made the ticket.