I downloaded and had a look. I reset the render node settings to defaults, that's min' 1/max' 16 threads(depends on how many processor cores you have, each processor uses 1 'thread', it can never exceed your maximum processors while rendering, even when you set 'max' to much higher than the number of processors you have, which I see is 8 ). And I reset the subdiv' cache to 400mb (default).
AA Bloom: A good setting to check in almost any render, and especially here in this one. It takes away the over-sharpness of bright highlights by 'blooming'(kind of like blurring) them at AA time. Without this setting checked, highlights on water, for example, will look very sharp and unrealistic. Keep it checked, I'd say.
Preallocate subdivision cache: As I understand it, this will apply the given amount of RAM to each and every render tile(bucket) you have running. If you have this set too high for the amount of RAM installed on your computer then TG will tell you it was unable to allocate that memory and that render bucket will fail. As an example, in your file you have a subdiv' cache of 900mb but 8 maximum threads, if you only have 1gb RAM installed on your machine(which I can see you don't) then nearly all of that RAM is being preallocated to one single thread, leaving none for the other 7 threads(and the rest of your computer, too) to use.
Someone else might explain this better/more correctly, it's a setting I never need to use. I'd uncheck it for this scene, it shouldn't need that much RAM per bucket as you have no extra 'heavy' objects requiring lots of RAM.
Do ray traced shadows: Leave this setting checked in the renderer node. It will calculate correct shadows from terrains and other scene elements.
Pixel filter: This is pretty much down to your own taste. For sharp images, use 'Box', for soft use 'Cubic B-Spline'. In this scene an AA level of 3(default) should be fine. You have no real need to go higher. In fact, you might even go lower by adjusting the 'pixel sampler' to use AA=3, 1/16 samples. Here are some examples that Oshyan from Planetside posted some time ago;
http://forums.planetside.co.uk/index.php?topic=5142.msg53401#msg53401 Atmosphere: I dropped the atmo' samples from your setting of 64 to 32 and I've rendered the top half of your image so far in under 30 minutes on my 2 threads. There is no 'noise' in the atmosphere.
What I would say that is adding lots of unnecessary render time to this scene is the GI settings. I would completely disable GI(set relative detail and sample quality both to '0'), the scene is completely backlit and you have no features in the shadows that require GI to brighten them up. GI is unneeded and will add an extremely long time to the rendering, for no real effect.
A render detail of '1' is unnecessary as well, especially at this size, unless you need a pixel-perfect render for production purposes. A level of '0.5' should be fine for this scene. I've set it to '0.6'. You'll rarely need to go higher than '0.8' for really excellent results. See these posts for detailed explanations on render/AA/Ray tracing settings;
http://forums.planetside.co.uk/index.php?topic=6442.0http://forums.planetside.co.uk/index.php?topic=8300.0I am rendering the scene just now, I don't know if I'll have time to finish rendering the water part. I'll post a link to however much I can complete and you could probably get away with crop-rendering the water portion and joining the two parts in an image editor program. All the settings are pretty much halved from the ones you uploaded and it is still very good quality and fast. Just don't assume that cranking levels will give the best results, lots of times you'll see no visible differences between settings but the render times will be significantly different. It's a balancing act, rendering with TG.
