Looking much better with the production engine. You should not need to change anything in the Output tab, except to disable Simulens features (if they are enabled), if the aim is to reduce render time to the absolute minimum. One more important thing to mention here regards the Maxwell Fire Settings window again, and that is the Threads setting: 0 threads means that Maxwell will automatically check how many threads (that is: CPU cores * threads per CPU core, so typically 8 threads for an Intel quad core with hyperthreading) are available, and use them all. Otherwise, you can set the desired number, in case you want to keep working on the machine while rendering (using all threads will tend to bring the machine to its knees).
Regarding the overall brightness of the image, I will make the assumption that most of these lights are meant to be fluorescent, in which case the Efficacy of 12.7 is likely too low. For example, wikipedia indicates (here
wikipedia -> fluorescent lamp -> luminous efficacy wrote:The efficacy of fluorescent tubes ranges from about 16 lumens per watt for a 4 watt tube with an ordinary ballast to over 100 lumens per watt with a modern electronic ballast, commonly averaging 50 to 67 lm/W overall.
It will not be an exact science, unless you have manufacturer data on the lights, but you can use information like this as a guideline. Aside from that, with the production engine, I would not pass judgement on the lighting of a scene like this until around at least SL8 or so -- it can be a good idea to drastically reduce the output resolution and render a test, if there is any question. However, with camera and lighting using realistic values, that should not usually be necessary.
As far as render time to finish is concerned, I would not expect this scene to take that long, though it is not possible to say, without knowing about the machine, and the number of threads being used for rendering. Regardless though, it may be worth mentioning, what I'd generally recommend once you are ready to render the final image is to:
- Set Maxwell Fire Settings > SL to a very high value (25-30), to prevent Maxwell from ever stopping on its own.
- Use all threads and leave the machine alone, in order to allow Maxwell to take full advantage of the hardware.
- Engage the "Lock" toggle-button in the Maxwell Fire window, to prevent inadvertently restarting the render.