Laptop HDD's

I'm getting a Alienware 15" for my study (game development...) With an pci ssd for OS and important software. But the 1TB HDD in that does seem a bit small... Though it runs at 7200 rpm. I don't know much about hdd's but if I'm looking for a 3TB drive I only find 5200 rpm drives. Does this make the bigger drives slower?
I currently run my games off an external HDD and I'd like to all of them on the internal drive so I'm guessing what to do... Get a bigger but slower drive or be stuck with an external HDD for my games.... What's your guys' advise on this?

Please correct me if I'm wrong in thinking rpm = speed ^^

yes having the slower RPM drive makes a difference in performance, for bulk storage like music and what not, dont worry about it too much. What 3 TB drive are you look at also?

@Hadesfriend I was looking at a Seagate laptop HDD and a WD blue line...
I primarialy want the drive for games but the stock 1TB with higher rpm(a toshiba I believe..) is better for these kind of things right? :/

Thanks for the response :)

Do u really need 3 tb of storage on ur laptop? If so then get the bigger drive if not then the smaller faster one would be better.

@Hadesfriend okay I think I know enough! Gonna think on it for a bit!
Cheers for the advice :)