The computing power of raspberry pi is limited and so is the access speed. I have 2 raspberry pi and was hoping I could somehow connect them together and make them work in parallel to get better and faster performance. My main usage of Ras-Pi is going to be running a local NAS, HTPC and a web-server w/ limited development. All of this to be used by my Macbook, TV and some remote access and backup. I am also planning to stream content through it. I tried to do all of it and the performance was really poor. I am looking for a way to make it faster either using these 2 raspberry pi I have or some cheap upgrades or mods.
Split the tasks, have 1 dedicated to HTPC and hosting the NAS/SMB server; keep this as a media pi. Use the other one as the web server or hosting pi. You can split these tasks however you want. The SMB/NAS pi will obviously be limited by the speed of the USB drive connected to it.
This guy used 64 to create a 'super computer' http://hackaday.com/2012/09/12/64-rasberry-pis-turned-into-a-supercomputer/
Steps on how to do it: http://www.southampton.ac.uk/~sjc/raspberrypi/
It will teach you how to create a 2 node computer. Test it out, looks interesting!