Between AMD Athlon XP 64 or Intel Core Duo's which one is better for running videos plus over a projector and possibly having two videos playing at the same time for a few seconds.

Did you meant athlon 64 x2 vs Core 2 duo? If that is the case, then Core 2 duo...

TMP-Man

Asus P5P800 PAT
P4 506 @ 4009Mhz 1.3v
Thermaltake CLP0024 w/ 1700RPM 92MM + AS5
2GB OCZ 2-3-2-5 DDR400
120GB/300GB 7200RPM HD
Leadtek 7600 AGP 590/1600 VF700 ALCU AS5

Yes, sorry. Was comparing both as duo core.

It's price vs preformance. Core 2 duo's are better in preformance when matched with the same level of an Athlon X2, but Athlon X2's are cheaper. So it will all boil down to how much money you are willing to spend. If your on a budget Athlon X2's are the way to go if you aren't then Core 2 Duo's are the way to go.

AMD Athlon 64 X2 4400+ OC 2.7ghz
4GB Dual Channel DDR 3200
Nvidia 7900GT
SATA II 2x 300gig 7200rpm 16mb cache RAID-0+1
Gigabyte Nforce 4 SLI

If you have enough RAM and a fast hard disk, both the CPUs will do the job. In fact, pretty much any CPU out in market today will be able to handle decoding (and playing) two videos at the same time.

I can play two videos simultaneously and still have programs running in the background on my single core 3000+ on 1GB RAM and the 7200.9 160GB Barracuda.

The X2 must be able to do that as well.
So, if thats your primary concern, go with the X2 and save up some cash. Invest it in a larger hard disk / more RAM / better video card / or just keep that money for a rainy day.

Kailas Shastry

3000+ Venice, A8N-E, 512MB x 2, 160GB Barracuda, 380W CM