Hi there.
I did some testing of the various acceleration structures in blender 2.53.
On Linux Mint 32 bit, Athlon 64 X2 4200+ 2.2 GHz Dual core, 4 GB DDR RAM.
I used 2 scenes; you can download them here and here.
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SCENE 1: Grass, 450K Verts.
Instancing on. (where applicable)
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SIMD QBVH -- 0:22.85, 0:22.89, 0:22.35
100M Peak
SIMD SVBVH -- 0:22.28, 0:22.34, 0:22.78
100M Peak
vBVH -- 0:27.30, 0:27.50, 0:27.46
115M Peak
BLI BVH -- 0:37.72, 0:37.71, 0:37.71
100M Peak
Octree (64) -- 0:22.93, 0:22.84, 0:22.81
125M Peak
Octree (128) -- 0:23.30, 0:23.18, 0:23.13
150M Peak
Octree (256) -- 0:29.07, 0:28.68, 0:28.93
165M Peak
Octree (512) -- 0:41.54, 0:41.59, 0:41.15
240M Peak
Auto -- 0:22.80, 0:22.35, 0:22.36
100M Peak
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SCENE 2: Raytracing!, 8500 Verts, 8sample glossy reflections, 4sample AO, 4sample area lamp.
No instancing (no need)
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SIMD QBVH -- 0:57.61
25M Peak
SIMD SVBVH -- 0:53.59
25M Peak
vBVH -- 1:09.53
25M Peak
BLI BVH -- 2:30.52
25M Peak
Octree (128) -- 3:39.78
35M Peak
Octree (64) -- 2:28.21
25M Peak
Auto -- 0:53.72
25M Peak
So, I’ve provided the results, would someone care to explain them?