According to my own experience with a notebook with Intel dual core 2.4 Ghz and 4GB RAM (W7x64, PPro CS5) is likely a CPU with 2.13 Ghz be too slow for smooth playback of 1080i timeline material.
For 1080p50 ranging from not then anyway.
For 1080p50 ranging from not then anyway.
Quite the contrary ... more image information is available, the less the computer requirement.
With 50p you lie so much better than with 25i.
And the question of computing power can be answered only if you know which profiles have been used in AVCH264.