Hi All - thanks for the replies so far...
The graphics card my Thinkpad T61p is using is the Nvidia Quadro FX 570M with the following spec:
Codename G64GLM 
Pipelines 32 - unified 
Core Speed * 475 MHz 
Shader Speed * 950 MHz 
Memory Speed * 700 MHz 
Memory Bus Width 128 Bit 
Memory Type GDDR3 
Max. Amount of Memory 256 MB 
Shared Memory no
 
DirectX DirectX 10, Shader 4.0 
Current Consumption 35 Watt 
Transistors 289 Million 
technology 80 nm 
Notebook Size medium sized 
Date of Announcement 01.06.2007 
Information Powermizer 7.0, CG Shading language, 32 bit floating point precision, 12 bit subpixel precision, 128 bit graphic pipeline, vertex and pixelshader programmability, PureVideo HD, PCI-E interface, FSAA with turned grid, nView multidisplay support, high-precision dynamic-range (HPDR) technology, hardware 3D clipping, full image antialiasing 
So Win 7 or XP..? Does 7 use a lot more CPU & memory than XP?