I have old philips 107T5 CRT and Nvidia graphics card. I used old Nvidia driver (but it wasn't 'legacy' one when I installed it) for few years but recently I decided to install other Linux distribution. I used 75 Hz refresh rate and 1024x768 resolution on my previous distribution.

After I installed the new distribution I had to install a Nvidia driver so I downloaded one from the Nvidia site (this time only legacy supported my card so I downloaded legacy and installed it). It wasn't automatically updating xorg.conf but I had my previous xorg.conf copy and I used it. When I run X I could only choose 85 and 75 Hz, 85 was checked as default.

And now what shocks me: that default 85 Hz looks identically like 75 Hz on previous driver looked (at least to me). I tried 75 Hz out of curiosity and it's too bright, hurts, etc. But on the previous driver 75 Hz wasn't hurting my eyes. Why is it different? It's the same number after all, so it should always give the same results, right? That's my first question.

Second question: Is 85 Hz OK for that monitor model? Would it break it? I tried to find the optimal refresh rate for this model but couldn't find it.