GI Cache... how to proceed?

[Dune]

I am about to make my medieval village at about 10000x3000px (probably detail 0.65, AA 8, GI 2/2, soft shadows at 0.8, samples , and don't quite know how I'd go about the GI cache file. Do I check that and run the complete (uncropped) file, or do I have to crop in advance (I probably want to make 2-3 crops to be sure and check halfway, and not let it run too long (always afraid it crashes))?
Does it stop after the GI cache file is written, or just continue?

Anything in particular I have to pay attention to?

[Kadri]

Yep,that you use the Alpha and we don't have it.
Beside this i envy you, Ulco. Just that you know  

[Dune]

Yeah, I know, I'm priviliged. And deeply thankful for that. You probably don't have to wait that long for 2.4, and then we  will have taken out all the mistakes. I mean 'we' with a 

[Kadri]

LOL i get it 

[freelancah]

Hmm..have you considered rendering the GI-cache (uncropped) with  a lower resolution than what the final will be? I'm not sure about the exact impact of this in terragen but I do it in Mental Ray all the time.

I'd atleast try to render lower res GI cache and use it for the 10k image, perhaps ½ resolution GI or even less?

[Henry Blewer]

Try 1/5 of the horizontal resolution. This seems to work for me on animation.

[Oshyan]

I think you should ask this on the alpha forum Ulco.

Also for an image at that resolution you should seriously consider using the RANCH Computing render farm service. Note that you would need to compute the GI cache ahead of time on your own system, in full. But this should not take too terribly long, and you can use say a 1/4 resolution render to create it, to save render time and file size. If absolute GI detail is critical, you could increase GI Relative Detail a bit in your 1/4 resolution cache file, though keep in mind that GI Cache file size is dependent both on image resolution *and* GI Relative Detail.

- Oshyan

[Henry Blewer]

Hmm. Does this mean the GI settings/calculation will be different in the next update?

[Dune]

Sorry, Oshyan, you're right of course. I'll manage on my i7 I think (I haven't purchased it for nothing), as a 6000px wide image renders in just over 2 hours at slightly lower settings and no soft shadows. And for such a large image, viewed at a little distance in a quite dark subterrainian parking lot, I think it needn't be thát perfect.
I'll try the 1/4 resolution GI pass first. Then set the resolution on what is needed, and render out 4 crops or so.