Rendering: Faster, Processor! - Blender Foundations: The Essential Guide to Learning Blender 2.6 - page 329

You'll notice the effect when rendering the example scene, as it seems to work in chunks. These
chunks are the tiles.
Postprocessing: By default, Blender sends all renders through both the compositor and the sequencer.
We haven't messed with either of them yet, but we will. Dither adds noise to the final image, and
is useful if you see banding in image backgrounds or on surfaces.
Stamp: We looked at the Stamp options when working with character animation.

Speeding Up Test Renders
While you're working on surfacing and lighting, you need to constantly render your scene to see how
you're coming along. The faster you can get meaningful feedback on your tests, the better able you are
to refine your work. The two ways to speed up renders for test purposes are by reducing the render
dimensions and reducing quality. Figure 12.3 shows a full-size, full-quality render of the example scene.
You can refer back to that as we go through the different ways of increasing speed for comparison. This
render took 9 minutes and 25 seconds
(9:25) on a system running Ubuntu
Linux 64-bit, Intel Core2Duo, 4GB
RAM.

If you are just going for overall impres-
sions, as you might be when working
with lamp settings, reducing the resolu-
tion by using the percentage slider on the
Dimensions tab is ideal. How small
should you go? The answer is another
question: How small can you stand to
look at? Figure 12.4 shows the scene
rendered at 15% size.

Figure 12.3 The full-size, full-quality render.

Another way to reduce the size of the
render without reducing the resolution is
to set a Render Border. For example,
when working on a shirt material, you
need to see a high quality of a portion
of the shirt, at full resolution. However,
you don't need to see anything else in
the scene. You could create a new
camera, zoom it in so that nothing shows
but the shirt, and render from there. A
better solution though, is to enter a
Camera view (Numpad-0) and use the
Border operation, which is triggered Figure 12.4 15% size; time: 1:08.