Blender crashes when decimating hi-poly mesh I just recieved a terrain mesh with over 16M polys.
I can open it and mess around the scene quite well since I'm on a really decent PC.
But I'm trying to decimate it (using the modifier itself) and my PC just crashes. It gets stuck for a while and then the sound and signal dies and PC freezes forever.
I haven't tried letting it frozen for more than 10min but since the sound on the PC dies I'm assuming it won't get out of the dead lock.

I don't think I'm recieving a less hi-poly version of that mesh, so I don't know what to do.

Thanks.
Make sure you have the newest release of Blender.
Recalculate normals, then try Clean up options on the mesh.
Maybe you'll have more luck that way than through the modifier.