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Brutal and Punishingly Long Renders

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Offline ACDmvmkr

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I'm trying to do animation sequences of rather detailed models, using both raytraced shadows in the scene and clear and reflective elements. This results in render times that can excede several minutes per frame. Even after thoroughly auditing the scene for any and all simplifications I can make, and unnecesary materials that I can dissable the ray tracing on, I still get these long render times.

I'm not complaining about the times, I know it's the price to pay for using those features to get the great imagery effects, but I am worried about what doing these sequences will do to my machine  when I start trying to render them out. I keep the ports and cooling fans clean, but other than that, and auditing scenery for simplicity and unnesesary RT active materials, I'm short of ideas here.

During any render job, my machine just dives in and shrieks full bore running at an absolute 100% capacity for each entire frame, with just a brief set-up occuring between each frame, where the workload appearently relaxes and appears to stem the heating process when the frame times are short enough.

I can usually achieve, and am happy with, render times of between 4 and 10 seconds per frame, as there is enough pause and reset time between them to keep my machine from overheating. But these longer times really worry me, as my core temperatures shoot up to become outrageously hot on just one frame.

Is there a way I can "throttle down" the "effort" (sorry I don't know the terms for this stuff) that my machine puts into doing these render jobs, like a setting in Blender that will tell the machine to run at only 50%, or say 30% capacity while doing these jobs? I could be comfortable just setting it up to run for hours at a time that way, or overnight with a restriction like this.


Offline kat

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You might try setting the system Processor Priority. With Blender open access Windows Task Manager (right-click the Task Bar, select "Start Task Manager"). Once this opens click the "Processes" tab then find the entry corresponding to Blender (usually "blender.exe"). Right-click this and click "Set Priority" then choose "Below Normal" or "Low". Note this doesn't change how much CPU/GPU resources are used to parse Scene data, only the order in which the system will action that specific task - if more important tasks need to run, those will be prioritised.

Other than that you're essentially getting into the realms of features possible available in third-party render software. And even then you're still going to have extremely high CPU/GPU usage due to the nature of number crunching in this context. So the only practical option is to try different things to cool the system, from clip-on fans for laptops to directing a desk fans at the inside of an open tower case (NEVER use an AC unit to do this as the moisture they produce will destroy your computers innards). Beyond that it means spending moocho-money on larger and more effective direct cooling.