Overclocking Results Show We’re Hitting the Fundamental Limits of Silicon

Overclocking Results Show We’re Hitting the Fundamental Limits of Silicon

Silicon Lottery, a website that specializes in selling overclocked Intel and AMD parts, has some 9900KS chips available for sale. The company is offering a 9900KS verified at 5.1GHz for $749 and a 9900KS verified at 5.2GHz for $1199. What’s more interesting to us are the number of chips that qualify at each frequency. 31 percent of Intel 9900KS chips can hit 5.1GHz, while just 3 percent can hit 5.2GHz. The 5.2GHz option was available earlier on 11/4 but is listed as sold-out as of this writing.

The 9900KS is an optimized variant of Intel’s 9900K. The 9900K is Intel’s current top-end CPU. Given the difficulties Intel has had moving to 10nm and the company’s need to maintain competitive standing against a newly-resurgent AMD, it’s safe to assume that Intel has optimized its 14nm++ process to within an inch of its life. The fact that Intel can ship a chip within ~4 percent of its apparent maximum clock in sufficient volume to launch it at all says good things about the company’s quality control and the state of its 14nm process line.

What I find interesting about the Silicon Lottery results is what they say about the overall state of clock rates in high performance desktop microprocessors. AMD is scarcely having an easier time of it. While new AGESA releases have improved overall clocking on 7nm chips, AMD’s engineers told us they were surprised to see clock improvements on the Ryzen 7 3000 family at all, because of the expected characteristics of the 7nm node.

AMD and Intel have continued to refine the clocking and thermal management systems they use and to squeeze more headroom out of silicon that they weren’t previously monetizing, but one of the results of this has been the gradual loss of high-end overclocking. Intel’s 10nm process is now in full production, giving us some idea of the trajectory of the node. Clocks on mobile parts have come down sharply compared to 14nm++. IPC improvements helped compensate for the loss in performance, but Intel still pushed TDPs up to 25W in some of the mobile CPU comparisons it did.

I think we can generally expect Intel to improve 10nm clocks with 10nm+ and 10nm++ when those nodes are ready. Similarly, AMD may be able to leverage TSMC’s 7nm EUV node for some small frequency gains itself. It’s even possible that both Intel and TSMC will clear away problems currently limiting them from hitting slightly higher CPU clocks. Intel’s 10nm has had severe growing pains and TSMC has never built big-core x86 processors like the Ryzen and Epyc chips it’s now shipping. I’m not trying to imply that CPU clocks have literally peaked at 5GHz and will never, ever improve. But the scope for gains past 5GHz looks limited indeed.

Power per unit area versus throughput (that is, number of 32-bit ALU operations per unit time and unit area, in units of tera-integer operations per second; TIOPS) for CMOS and beyond-CMOS devices. The constraint of a power density not higher than 10 W cm2is implemented, when necessary, by inserting an empty area into the optimally laid out circuits. Caption from the original Intel paper.
Power per unit area versus throughput (that is, number of 32-bit ALU operations per unit time and unit area, in units of tera-integer operations per second; TIOPS) for CMOS and beyond-CMOS devices. The constraint of a power density not higher than 10 W cm2is implemented, when necessary, by inserting an empty area into the optimally laid out circuits. Caption from the original Intel paper.

The advent of machine learning, AI, and the IoT have collectively ensured that the broader computer industry will feel no pain from these shifts, but those of us who prized clock speed and single-threaded performance may have to find other aspects of computing to focus on long-term. The one architecture I’ve seen proposed as a replacement for CMOS is a spintronics approach Intel is researching. MESO — that’s the name of the new architecture — could open up new options as far as compute power density and efficiency. Both of those are critical goals in their own right, but so far, what we know about MESO suggests it would be more useful for low-power computing as opposed to pushing the high-power envelope, though it may have some utility in this respect in time. One of the frustrating things about being a high performance computing fan these days is how few options for improving single-thread seem to exist.

This might seem a bit churlish to write in 2019. After all, we’ve seen more movement in the CPU market in the past 2.5 years, since AMD launched Ryzen, than in the previous six. Both AMD and Intel have made major changes to their product families and introduced new CPUs with higher performance and faster clocks. Density improvements at future nodes ensure both companies will be able to introduce CPUs with more cores than previous models, should they choose to do so. Will they be able to keep cranking the clocks up? That’s a very different question. The evidence thus far is not encouraging.

Continue reading

Fermilab Experiment Hints at New Fundamental Force of Nature
Fermilab Experiment Hints at New Fundamental Force of Nature

The team working on Fermilab's Muon g−2 experiment has reported a tantalizing hint of a new type of physics. If confirmed, this would become the fifth fundamental force in the universe.

Affordable 5G Could Fundamentally Change How You Receive Internet Service
Affordable 5G Could Fundamentally Change How You Receive Internet Service

5G service could collapse the distinction between cellular provider and ISP, fundamentally changing how consumers buy internet service — but only if that service is kept affordable.

Is Hyper-Threading a Fundamental Security Risk?
Is Hyper-Threading a Fundamental Security Risk?

Has Intel's Hyper-Threading support become a fundamental security problem? Theo de Raadt, founder of OpenBSD, argues that it has.

Intel’s Fundamentally New MESO Architecture Could Arrive in a Few Years
Intel’s Fundamentally New MESO Architecture Could Arrive in a Few Years

Intel's new MESO architecture could appear in products more quickly than anticipated, particularly in AI.