Although the best mobile phones need the most advanced chips to be competitive, 5G radios simply have to be able to perform their functions effectively. Radios, unlike phones, have room and power for 2 or 3 slightly less efficient chips. The necessary functions can be split between two chips or three chips, each optimized for the many different functions required by the 5G radio. Huawei will neither confirm nor deny this is practical, so I am reaching out to chip experts.
There are many different ways to measure efficiency and experts disagree on how much more efficient 7 nm chips are than 12 nm, the best that can be produced today at SMIC in China. Estimates range from 20% to 50%, and there’s no simple way for a firm estimate until chips are available for test. Almost certainly, two 12 nm chips can match the functions of one 7 nm chip. A third chip could be optimized for functions that needed the most speed.
The 2 or 3 chips can be delivered as “chiplets,” which AMD and others are demonstrating can be very effective. 2-8 chips are combined into a single package with custom-designed high-speed interconnections. AMD’s Mark Papermaster is the pioneer here, using a chiplet design to quickly bring the Epyc server chip to market.
“I think the whole industry is going to be moving in this direction,” Papermaster tells Wired. Smaller chips are much faster and less expensive to design. They also are less sensitive to defects than a monolithic chip. On a monolithic chip, a single defect means it must be destroyed. If broken into three separate chips, the other two parts are still fine. AMD engineers estimate the cost is halved.
Ramune Nagisetty of Intel agrees. She calls it “an evolution of Moore’s law. Intel has a very deep roadmap for chiplets. This is the future.” Intel is already shipping a processor for mobile PCs that combines an Intel CPU with a graphics module from AMD. Intel sees its future as chiplets, including a project called Client 2.0.
Of course the performance of 12 nm chips does not match what’s possible in 7 nm. But with good design, much of the gap can be closed. There’s a cost involved, but it’s not material to a radio selling for $5-10,000.
Tough years ahead if the U.S. continues the blockade but Huawei will survive.