Faster a portion of technology evolves, sooner it risks to hit a plateau. Hard disk manufacturers are currently facing this challenge since 2010 when they managed to fit 1TB of data per platter of a HDD. That's pretty much the maximum limit and now the companies are up against the wall to push the technology beyond the barrier. Western Digital is experimenting with Helium filled drives to tackle the problem. On the other hand, Seagate thinks its new technology called SMR is the answer to all the troubles. Seagate, on Monday, announced it had already sold 1 Million drives using SMR and they'll sell 5TB hard disk drives from 2014 onwards. Not only that they plan to sell 20TB HDDs by 2020.