HDD setup for Win 7, which is best?

[DoubleCheese]

Currently I've got two WD 250GB HDD's in my XP box and a 1TB WD Green for backing everything up to.
If I kept the two 250GB drives and installed Win 7 in RAID0 would it be as fast or faster than a 1TB WD Black drive? I'm also concerned about heat, noise and power efficiency. Does the 1 new drive make more sense than two 3-4 year old ones, for reliability too?
The PC is mainly for photo and a little video editing/processing.

Thanks.

 

[Randomface74]

I'm also gonna get a new HDD for my Win7 installation. I'll likely get a single Segate 1TB drive.

 

[ArtificialFoxx]

1 new drive would be more reliable than a raid0 setup with two old drives because you will only need one of those older hdds to fail and all your data will be lost. (so you have at least 2x the chance of failure)
I have found that going from a single drive to two (on mobo raid0) can get up to about a 50% increase in sequential read speeds, but unless you are often copying large files across your drives then the performance increase will be minimal, or even lowered seek times