There are disks of 150 GB and 500 GB already in market from sea gate. Now this 1 TB 3 1/2 inch 7200 rpm drive from Hitachi. It has 32 mb cache and costs 29,300. Although 2 500 GB hard disks would cost you only a 13,000 Rs cost and works cheaper.
The hard disk is consisting of 5 platters, emits more heat and has higher response time . But compare it with this it has 10 times the density of ordinary disks as it uses a PMR ( Perpendicular Magnetic Recording ) compared to longitudunal recording.
All in all computers are all set to store Data Mines in Them.