Performance with caustic sampler

Slartibartfast

Hi! I've been working in Daz Studio for quite a few years now, and my relationship with the caustic sampler has been hit and miss. For the first few years, enabling the sampler would cause my computer to slow to a crawl while rendering, making everything sluggish, unresponsive, and laggy. Then, something happened (I wish I knew what) that caused the caustic sampler to no longer do these things. I was able to enable it in any scene that felt like it might benefit without any noticeable performance cost in Windows. This went on for a while, and then I had a catastrophic HD failure that forced me to reinstall Windows.

And now, lo and behold, the caustic sampler is all laggy again, even in the same projects that rendered smoothly before, using the same settings (as far as I can tell, anyway). 

Does anyone have any idea what I might have done previously to make the caustic sampler so much smoother? It shouldn't be related to project settings since those are stored alongside the project and thus should have transferred to my fresh install. 

For the record, I'm using Windows 11 on an i7-12700K with a GeForce RTX 4090 and 64 GB RAM.