Phase-Change Memory Expands Potential Capacity by More than a Bit

Phase-Change Materials Could Improve our RAM

Advances in computer memory are going on all the time. Just recently it was announced that science has managed to represent a usable bit with just 12 atoms. Now there’s an advance that puts that to shame. It’s called Phase-Change Material, or PCM.

PCM memory stores information by changing the material from an amorphous state to a crystaline state. The cool thing is that the degree of amorphousness can be varied, meaning that you’re no longer going from just one state to one other state. You have a whole range of states that can be switched between.

In other words, you’re no longer dealing with just zeroes and ones.

Possibilities for the Future

There are two exciting directions this could take us.

1. We could leave the old-fashioned, stuffy antiquated world of binary computing behind forever and go trinary, or heck, even work in base 16.

2. We could keep going with binary and the wealth of technologies that use it.

#1 is kind of unlikely to happen any time soon since we do have so much invested in binary. Compatibility between technologies would be a big and unnecessary problem.

Instead, option 2 is very promising because if you’ve got a material that can switch between 4 states (for example) there’s no reason that one PCM bit can’t represent 2 traditional binary bits. The result? Super-dense memory using less physical space and potentially less power, too. And if it uses less power, it’ll generate less heat. Wins all around!

Even better, 4 states is a simplified example. Apparently researchers have already demonstrated not just 4, but up to 512 discrete states on a single 20-nanometer PCM cell.

I can just about see the era of RAM measured in exabytes comin’ round the corner any day now…

(via New Scientist)