Last week’s Intel Developers’ Forum brought the expected crop of new CPU chips. The simplest way to summarize what’s taking place is this:
- We’re stuck at 3GHz, so we add more processors on the CPU chip.
- Intel continues to lead with small “geometries”, 32 nanometers today, 22 nm tomorrow.
- The company pitches its x-86 processors for mobile devices.
More processors: Once upon a time, each year brought a significant increase in processor speed. Not to be too wistful about the early PC days, but a 1 MHz processor ran “perfectly good” spreadsheets. Like many bouts of nostalgia, this one omits important bits of context such as the complexity of said VisiCalc model, what other software ran concurrently, if any, what storage and networking devices were supported, what kind of display and audio devices were offered. Still, I’d love to see the original assembly language version of Lotus 1-2-3 run on a “bare metal” DOS configuration brought up on a 3GHz Intel machine — a CPU clock 3,000 times faster than the 1983 vintage machine.
In the early 90’s, luxury was a 33MHz Pentium. Now we’re at 3GHz, apparently stuck there for the last 4-5 years. (A history of Intel processors can be found here.).
The faster you move something around, the more power you need. Try lifting and lowering a 10 pound weight. Slowly at first, once every 5 seconds, then every second, then twice per second. Your own body temperature will give you the answer.
Inside a processor, we have transistors. These are logic gates, they open and close. In doing so, they shuttle electrons back and forth at the circuit’s clock speed. These electrons are not “weightless”, moving them consumes power, just as we do lifting weight. As the clock rate increases, more power is needed, the transistor temperature increases. There are more precise, more technical ways of expressing this; but the basic fact remains: faster chips are hotter chips. Knowing this, chip designers found ways to counter the temperature rise such as using smaller gates shuttling a smaller “mass of electrons” back and forth. Air or liquid cooling of chips does help as well. Still, we hit a wall. With today’s (and tomorrow’s foreseeable) silicon technology, we’re out of GHz.
So, what do we do for more powerful CPU chips? More