Dude think about it. Just how much information is stored in one tiny cell of our body? The entire genetic makeup that makes us - us. Our entire body can be rebuilt with the information in any one of our cells.
And that demonstrates just how much we can store with DNA.
Notice the chemical reactions that take place in our brain and transmit various information. Just imagine how much input our brain recieves at every given moment about our surroundings and internal working processes. It's damn fast. And they say our brain is only using a small fraction of it's potential. DNA computers can harness some of that. Read the article before debating what I say - like jtendra should've. http://www.howstuffworks.com/dna-computer.htm