The strange thing is a couple of weeks ago I wanted to see how my PC will handle several characted, so I loaded about 5 figures, some of them were dressed in a bathroom with glass and reflective surfaces and Daz didn't crash.
I have 20GB swap file.
I guess I'll have to add some RAM soon.
That's indeed strange.
5 figures without clothes/hair should probably work, but with clothes and especially hair it will blow up the ram usage.
AFAIK reflective surfaces are not a big deal regarding ram (not vram), but they are increasing render times in iray a lot (might be wrong).