I shouldn't have brought up "mass production"...
Well, since I did - here are some explanations.
As
DuckSwim already said, there is a difference between a render where you go the extra mile for best quality (you can do with your current skill, including post work, etc.). That's what is done when creating a single render for DA or also for F95 as done by DuckSwim. This can easily take several hours or even days for just a single render.
Nowadays the "machine render time" is no longer that relevant. Not even with "just" 2 fast GPUs. The bottleneck is the human factor by a huge margin. Scene setup and composition takes far longer than the render itself. Since you can work on the next render while the PC renders the last one, as long as the machine render time is lower than your time, getting better or faster hardware won't help. With the last upgrades I'm easily at that point for >90% of the renders. At a certain point, even heat generation is a factor, especially in summer. Imagine a 700 Watt heater running in your room 10 hours a day...
"Mass production" is more like creating 10 renders or even more in a day. If the machine render time is 5 minutes or 15 is not important. More than 20 renders a day is more or less impossible to do, even for me.
I'm pretty sure I've explained a "standard" workflow somewhere already.
There are several steps when creating a number of renders in the same environment.
1) Scene and environment setup - including all probs and basic lighting (this is necessary for consistentcy between renders - you don't have to care about it when doing single renders)
2) Character creation - Doesn't happen that often now for HI, but had to be done with Sara, Daniela
3) Character adjustment based on scene/event - This includes selection of clothes, makeup, etc.
4) For each render - camera placement, character pose and expression setup, lighting adjustments, body adjustments (yes, I really do that based on the pose), clothes adjustments (poke through), hair adjustement, several test renders, especially for the first in a series of renders
Nr 1) is not done that often. E.g. only basically once for a new environment. Depending on the environment, this can take weeks in extreme cases (like with the 6 areas in the underground lab)
Nr 2) is also not done that often - but sometimes there are special scenes with modifed characters (e.g. muscle growth)
Nr 3) has to be done for each scene/event, maybe even more than once if a character undresses
Nr 4) this is where the "mass production" comes in - especially if there is little or no camera movement, the environment, character, lighting is reused several time. Only the pose and expression of the character(s) is/are changed.
This is the only time where the machine rendering can be slower than the human factor. But only if the clothes and hair play nice and don't need manual intervention. When the camera position is changed a lot, or the character placement is changed a lot, you almost always need to adjust the lighing as well. Now comes the tricky part - consistency with your other renders in the same scene and still good figure lighting. This takes time and test renders. So in that case, machine render time is not relevant. A test render normaly doesn't take longer than 1 minute.