Posted by Cary Chin on October 20, 2011
This blog originally posted on the Low Power Engineering Community 5/12/11.
It’s been an exciting week for designers of low-power electronics, as well as consumers of mobile devices. Intel announced on May 4 that its Tri-Gate 3D transistor technology is ready for production on its 22nm process. The “Ivy Bridge” processors are being demo’ed now and scheduled for full production this year. Products containing Ivy Bridge processors will ship in 2012.
Analysts have been salivating at this new technology announcement, with much written about how this technology unlocks Moore’s Law for the future and bolsters Intel’s competitive position vs. ARM for low-power processors. But there’s been some inconsistency and confusion in the press about the technical claims for this technology, so I thought it would be fun to take a closer look.
Intel’s press release states: “The 22nm 3-D Tri-Gate transistors provide up to 37% performance increase at low voltage versus Intel’s 32nm planar transistors. This incredible gain means that they are ideal for use in small handheld devices, which operate using less energy to “switch” back and forth. Alternatively, the new transistors consume less than half the power when at the same performance as 2-D planar transistors on 32nm chips.”
Sentence No. 1: A 37% performance increase for low voltage applications (mobile devices) sounds pretty impressive, but that’s pretty much in line with what I’d expect in moving the technology node from 32nm to 22nm.
Sentence No. 2: This one’s just in there for marketing purposes, although the grammar implies that the “handheld devices” are switching “back and forth.” That’s more than a little confusing, even for an engineer—or maybe especially for an engineer.
Sentence No. 3: The key word here is “Alternatively”. This implies that you get 37% better performance in low-voltage (low-power) mode, OR 50% less power for the same performance in high-performance (high-power) mode. “Same performance“ here isn’t well-defined, but I’m assuming that means equivalent transistor performance (delay), not operating voltage.
Several press accounts have reported 37% better performance AND 50% less power, which isn’t consistent with the press release.
So what’s the bottom line, and how big of a deal is this? First of all, we’re going into production at the 22nm node. Second, the so-called 3D technology is indeed a breakthrough because it enables volume production at 22nm without the anticipated and feared exponential rise in leakage current. Intel uses the analogy of a skyscraper in its press release. It looks to me to be more of a rooftop deck–but decks are still a big improvement. And yes, I am excited!