So I'm in the process of rendering a picture with an infinite terrain in it.  I have it set on user settings (I forget the exact settings, but it's nowhere near as high as I've been using recently) and so far it's been stuck at the 15% prepass for, well, about 10 hours.  Now, part of me thinks that it might actually be continuing to render nonetheless, but I'm not sure how long I'm willing to wait.  By this I mean that I'm wondering if it's not actually at 15% of the prepass but that, due to the extreme nature of infinite terrains, the computer might have frozen that number, so to say, while it's actually continued beyond it.....sheesh, sometimes I really wish I knew the exact terminology....anyway, any advice? 

Also, the "time left" hasn't changed at all either, which also leads me to believe that the numbers might just be frozen.  Normally it changes a lot, and it hasn't in about 10 hours. 

So I think I'll let it continue throughout the day and see if it eventually finishes, but I'm not sure if I'm willing to go for two or three days without knowing if it actually has just completely frozen.

Well, thanks again!

Do you have a dynamic ecosystem on your terrain?
What lighhting model do you use?

Actually, there's no ecosystem but the texture might be a bit complex.....as for the lighting, it's a similar model as I've used before...

That behavior is really strange... I suspect that's frozen.

Yeah, definitely not normal....The prepass is normally quite fast, unless you use radiosity with very high photon settings.

So I just got home from work and it was still at 15%, but now it said it was estimating 100 hourse.....for the prepass!!!!!  Anyway, so I stopped it, restarted it, made the infinite terrain's texture simpler, and used new user settings that were about half what I had them at before.....I'll let you know how it goes.....

And I just checked and it's at 17%, so that's a good sign.....I wish the infinite terrain didn't look so damn good, else I'd change it, but I feel it really makes the picture work so I'll deal with what looks like a long render time (I'm used to it).....

It froze at 25% so I gave up, created a regular terrain to fill in the gap left when I deleted the infinite terrain, and now things are coming along fine.....

Did you have displacement in your infinite terrain's material?

No, it was pretty complex though.....but even after making it a simple texture it didn't get very far before it froze.  My system resources were getting pretty low too (even though I had saved and reloaded it before attempting to render).  It's a good thing I stopped it and got rid of the infinite terrain because there were some major flaws I needed to fix, and had I waited a couple days to find out I would have been pissed.  As I said before, it's time for a new computer dedicated solely to Vue.  I'm going to get a new one soon....actually, I posted a message asking what the perfect Vue computer would be but I dont think I saw a response from you, and I really value your wisdom in these matters.....

I didn't reply on that thread because I figured you already had several good advices, I wouldn't add anything much relevant. But, since you asked :-) I will add my two cents there now.