Single model workers configs should mean a less aggressive memory cleanup scheme

[tazlin]

The primary intent behind leaving a certain amount of free system ram is to allow a cushion for potentially very large other models to load (such as SDXL models). However, in the situation where the worker is configured only to run a single model, the memory conditions become much more predictable and will fail anyway if an OOM occurs.

• If the worker has one model only
  • If the model has only a single model file
    • Keep the model entirely on VRAM 100% of the time
  • If the model has multiple models (as is the case with Stable Cascade)
    • Avoid offloading to disk if possible, swapping the models only between RAM and VRAM.

If failures are met in this situation, its likely the model overhead would only be encouraging the worker to run in very poor memory conditions (as they would constantly be loading off disk for little to no reason).