Do pc games still run ok if being played from an external usb harddrive ?

I was thinking of buying this for my laptop http://www.amazon.co.uk/Iomega-Desktop-Hard-Drive-Value/dp/B0013E5G4C/ref=sr_1_1?ie=UTF8&s=electronics&qid=1211061231&sr=8-1

but will games still run ok if installed on it ?Does it have enough speed ? Or all games should be installed in sata harddrives? Thanks

It isn't the speed of the hard drive that is the issue but the speed of the usb bus. It is far slower than the current SATA bus speeds. If you can swing it I strongly recommend getting an internal drive.

Another point to concider is the installation of the software. There are some files installed into folders within the Windows OS. If you try and take the portable hard drive to a different computer the game probably won't work.