Can't render anything suddenly...

Everything has been working just fine.. but all of a sudden anytime I try to start a render Daz freaks on me. It is set to use only my graphics card with optix acceleration. Texture compression is at 524/1024 as it always is. The render isn't complicated, and it doesn't matter what is in it (I have tried with multiple things - I have rerun renders that worked perfectly before). It always does the same thing. It starts rendering, uses a tiny bit of the gpu.. and then goes jumps to doing everything on CPU takes that to 100% usage in memory and processing power and then crashes. If I am lucky it might not crash and it will render very slowly using the cpu. The enitire time it is doing this I have sat and watched the resource manager on my computer. It jumps my GPU memory use by a tiny amount and then jumps right to CPU. It is acting like I don't have a video card at all basically.
Any ideas? Because this is getitng very old very fast.
Comments
Do you have a GPU monitor running like MSI Afterburner or EVGA Precision X? Your VRAM might be full if you haven't restarted DS lately.
Also, "the latest drivers" is not always the right answer. I'm still running 387.92 because 388 had problems.
Have you tried switching off Optix accelleration? Don't know if it's still an issue, but that used to cause problems for random people.