Computer engineer here.

From the article:

it should be stressed that commercial 7nm chips remain at least two years away

That doesn't mean to expect commercial 7nm chips in exactly two years as some are speculating, it could mean that commercial processes are anywhere from two to seven years away. Keep in mind that this is a demonstration of a test chip produced on a research process. I've seen plenty of technology demonstrations that were years from being productized. Improving consistent process yields is of critical importance, as is developing the entire set of tools that engineers need to design chips to the new process technology.

With that reality check out of the way...

This announcement basically means that IBM has demonstrated a manufacturing process where they can build features on a chip that are 7nm in resolution. Put differently, imagine that they have invented a pencil that lets them draw lines that are 7nm across. This doesn't mean that a single transistor is 7nm wide, as a single transistor requires multiple features to create, but think of this as meaning a new process that lets future transistors be roughly 25% the size of the processors on current shipping high-end devices.

What good are smaller transistors?

The primary benefit is this lets engineers pack more functionality into a smaller space. This does several things, but basically it means we can make devices more powerful and have more functionality.

Some in this thread have speculated that this announcement will lead to lower power consumption or faster clock speeds. That is possible, but not guaranteed. Clock speeds have been stuck around 3 GHz for the past ten years not because of transistor size, but because of the difficulty of dissipating the heat generated. Heat roughly increases by frequency³ and smaller transistors aren't going to directly help with that.

Note that IBM doesn't directly claim a power improvement from this technology, instead they claim a "50 percent power/performance improvement". Ask yourself what does that really mean?

Let's define power/performance X as follows: * N = number of cores * f = clock frequency * power = Nf³ * performance = Nf * power / performance = (Nf^3)/Nf = f²

Note that basically the number of cores drops out and power/performance simply becomes the square of frequency.

What does this mean?

Since a smaller resolution transistor will allow engineers to put more cores on a die, and since the performance definition above implies that doubling cores doubles performance, we can effectively achieve a 50% improvement in power/performance by doubling the number of cores and dropping frequency by 1/sqrt(2).

Put differently; 4 cores running at 1.9 GHz offers a 50% improvement over 2 cores running at 3.0 GHz.

• power Consider a CPU with 2 cores running at 3 GHz. We can assign a power/performance rating to this of