The Poser manual states:

"You can adjust the cache size by clicking and dragging on the Irradiance caching slider. More caching means that ....  irradience values will be less accurate due to the increased amount of estimation. Less caching .... will result in longer processing times but increased accuracy."

But the render window help prompt says:

"Higher values increase detail in ambient occlusion and gather effects."

If the manual is correct, then zero on the slider gives no caching (= highest accuracy).

If the in-program prompt is correct, then 100 on the slider gives highest accuracy (= no caching). Also, if you copy the highest Automatic render settings into the Manual tab, it gives a value of 100.

Does anyone have a definitive answer on this?

"If I were a shadow, I know I wouldn't like to be half of what I should be."
Mr Otsuka, the old black tomcat in Kafka on the Shore (Haruki Murakami)