4200rpm to 7200rpm hard drive upgrade

Hi guys

So i'm thinking of investing in a new hard drive as my current one (160gb) is nearly full, and not wanting to slow down my computer do not want to fill it completely.

Now, my current hard drive is only 4200rpm as it's fairly old and was part of a prebuild when i bought it.

When installing games on my new drive (which will be 7200rpm. 16mb cache) will i see a difference in performance than when installed on my 4200rpm?

I know games such as Oblivion and Fallout read from the hard drive regulary so this would be interesting to know.

Could it be possible that my 4200rpm harddrive was a slight bottleneck on my overall gaming performance? (My other parts are fairly new)

load times will be a bit shorter , and lag will be reduced.

however, it may also be a bit louder.