"How does a faster graphic card help in video editing? ACtually does it help at all?"

Barely. We've tried AGP 4MB generics and high end 256MB video cards and the renders times don't budge. Since rendering is so 99% of the time we wait during video editing I'm going to write "no." I'll flipflop if you dig up some 10 year old TNT2 card.

"Could suggest a few home user oriented applications that are affected by a graphic card. For example I already know that a faster CPU helps in making a DVD faster, rendering video faster etc. More memory helps in dooing more work at once. etc."

Unless I list games...


"Another question I want to ask is that do most video editing and DVD authoring programs have multi threading and TLP (Thread Level Parallelism) for more than 2 cores? I understand that many many programs are optimised for dual cores but what about quad cores? Are they made in such a way like some scientific programs that they automatically use up as many cores as possible?"

Benchmarks will tell but let me share I owned a dual CPU Pentium Pro with the OverDrives. While that was all of a pair of 333MHz CPUs they would overtake and pass up an Athlon at 1GHz (or higher) when it came to video rendering to DVD. The parallel processing really shines on dual core.

For quad core I don't expect as much payback but still it can pay off as one core does decoding, the next encoding, the next OS tasks and one left over for what else. You will read pundits that will pan such setups but having owned them I think they are writing without the benefit of using such systems.

Bob