I have problems when tune HD channels. It looks slowest and stop. SD channels are perfect.
I see perfectly 1080p mkv movies on my HTPC.
I have windows 7 ultimate 32 bit with 4 GB of ram.
Any idea?
Basically HD TV is quite often 1080i (interlaced), which is harder for the GPU to handle because it has to de-interlace it (1080p is easier - no de-interlacing needed).
You'll definitely need to use DXVA2 hardware acceleration in LAV video decoder to reduce the CPU load (I don't think Atoms have QuickSync decoding).