First download
http://www.nvidia.com/object/mac-driver-archive.html
CUDA Mac Driver
Latest Version: CUDA 3.2.17 driver for MAC
Release Date: 11/16/2010
Test in Mathematica 8 with mac mini 3.1 early 2009, Snow Leopard 10.6.7
Needs["CUDALink`"] CUDAInformation[1]
{"Name" -> "GeForce 9400", "Clock Rate" -> 1100000,
"Compute Capabilities" -> 1.1, "GPU Overlap" -> 0,
"Maximum Block Dimensions" -> {512, 512, 64},
"Maximum Grid Dimensions" -> {65535, 65535, 1},
"Maximum Threads Per Block" -> 512,
"Maximum Shared Memory Per Block" -> 16384, "Total Constant Memory" -> 65536,
"Warp Size" -> 32, "Maximum Pitch" -> 2147483647,
"Maximum Registers Per Block" -> 8192, "Texture Alignment" -> 256,
"Multiprocessor Count" -> 2, "Core Count" -> 16, "Execution Timeout" -> 1,
"Integrated" -> False, "Can Map Host Memory" -> False,
"Compute Mode" -> "Default", "Texture1D Width" -> 8192,
"Texture2D Width" -> 65536, "Texture2D Height" -> 32768,
"Texture3D Width" -> 2048, "Texture3D Height" -> 2048,
"Texture3D Depth" -> 2048, "Texture2D Array Width" -> 8192,
"Texture2D Array Height" -> 8192, "Texture2D Array Slices" -> 512,
"Surface Alignment" -> 256, "Concurrent Kernels" -> False,
"ECC Enabled" -> False, "Total Memory" -> 265945088}