I bought a Geforce 7600 GS for my computer hoping this would be enough to run DVB-T without upgrading my entire pc, but silly me of course I found out after that nothing works properly with AGP!
So after much fiddling around reading this thread and following dat's instructions,
I have managed to get TV3 and C4 running fairly well at 20-25 fps using VMR9 and PDVD8 codecs. Whats weird is that I can only get 3-6 fps on TV1 and TV2!
My system specs (taken from dxdiag.exe) is:
OS: Windows XP Pro SP3
System Manufacturer: VIAK8_
System Model: AWRDACPI
BIOS: Award Modular BIOS v6.00PG
Processor: AMD Sempron 2600+, MMX, 3DNow, ~1.6GHz
Memory: 1024 MB RAM
Page file: 308MB used, 2151MB available
DirectX Version: DirectX 10.0 (4.10.0000.3311)
Geforce Forceware driver is v175.19