List of graphics cards supported by Snow Leopard (10.6.x) but not OpenCL capable? (In older Intel Macs.)
Based on Final Cut Pro X, Motion 5, Compressor 4: Graphics card compatibility those cards are


Intel Graphics Media Accelerator (GMA) 950
Intel Graphics Media Accelerator (GMA) X3100
ATI Radeon X1300
ATI Mobility Radeon X1600
ATI Radeon X1600
ATI Radeon X1900 XT
ATI Radeon HD 2400 XT
ATI Radeon HD 2600 PRO
ATI Radeon HD 2600 XT
ATI Radeon HD 3870
NVIDIA GeForce 7300 GT
NVIDIA GeForce 7600 GT
NVIDIA Quadro FX 4500