Out of memory errors at every single step. Possible reasons?

Hello there

After doing tons of research, I've learned that proper lightmap settings are crucial for a healthy baking - NOT the highest values you can get. So obvious stuff aside, I'm having a problem with my current scene and looking for suggestions, potential leads and maybe some experimentation ideas to fix the problem.

Using Unity 2019.2 beta.
Progressive GPU
1 Mixed Area Light (Huge)
7 mixed Spot Lights
15 Realtime Spot Lights.
Terrain is turned off for testing purposes.

The problem is that I'm getting "xxx job failed, out of memory" errors at every single step of the baking process. this applies to 5 jobs specifically. Progressive Lightmapper Gbuffer, Material render and AddMaterial jobs, Clustering jobs and LightTransport jobs. The requested memory ,s resulted around 28GB's of memory when I tried with Lightmap Resolution set to 16.

Also, when the Lightmap Resolution is set to 16, the baking never finishes (even after 14 hours) and as I check from the task manager, any usage on GPU and CPU stops after a certain job fails I guess.

Take a look at these settings:


After setting the LM resolution to 4 (joke?), I could finally get past baking and move forward to clustering and light transport phase but it took a gigantic amount of time and still did not finish after long hours as well.

Can anyone point me to a reasonable way to solve this? Any golden checklist for example? Or key points?
Thanks in advance.

 

Ah good question, forgot to add that

Specs:
GTX 1060 6GB
16GB Ram
i7 7700K CPU

Maybe still not tnough?
Tried the CPU, the amount of time is clearly increased but since I could literally never finish the entire baking process, can't say the exact amount of time it took to bake. But yeah it takes much more time, that's for sure. I'm thinking about something should be wrongly set in my scene but can't think of anywhere to look into...