The microchip era may be ending - and wafer-scale systems could be what comes next

Skye Jacobs

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Forward-looking: The engine of the digital age is running up against the laws of physics. Modern semiconductors, the microscopic foundations of computing, are nearing their physical limits just as artificial intelligence and high-performance data processing reach new heights of demand. The result is an industry-wide reckoning... and a search for what comes after the microchip.

Nowhere is this transformation more visible than at Nvidia, whose valuation recently soared to about $5 trillion, making it the world's most valuable publicly traded company. Nvidia's flagship processors are intricate marvels. Each unit – encapsulated in a plastic package and interwoven with copper connections – contains up to 208 billion transistors.

With a single chip priced around $30,000, these components offer unprecedented computational muscle, especially when arrayed by the thousands in data centers. Nvidia's recent architectural breakthroughs enable chips to operate collectively as large-scale hyperscale computers rather than as independent processing units.

AI's exponential compute needs, however, have led to a juncture dictated by the immutable laws of physics. At the heart of chip fabrication is extreme ultraviolet lithography, a process dominated by Dutch equipment maker ASML and its $380 million high-numerical-aperture "Extreme Machine."

This tool, which resembles a highly specialized camera, flashes light through precision photo masks onto silicon wafers to define circuit patterns.

Despite its sophistication, even the most advanced lithography system faces a fundamental constraint: the reticle limit. This physical law limits the size of a single chip die to about 800 square millimeters. As a result, achieving larger processing capacity requires partitioning computer tasks across multiple smaller chips interconnected by ever-denser packaging, cabling, and fiber links.

These architectural limitations are evident in the evolving design of modern data centers, where the trend is toward smaller "chiplets" interconnected to scale. Yet this fragmentation adds communication overhead, mandates ever more clever packaging innovations, and increases system complexity.

Confronted by both the reticle limit and the diminishing returns of incremental scaling, researchers and semiconductor firms are exploring wafer-scale integration. This model abandons conventional discrete chips entirely, instead using the full silicon wafer as a single, monolithic processing substrate.

Recent efforts by Cerebras, a Palo Alto company, have yielded the WSE-3 (Wafer-Scale Engine 3), which incorporates four trillion transistors and delivers 7,000 times the memory bandwidth of top conventional chips. Unlike standard architectures, WSE-3 embeds memory directly within the wafer, dramatically reducing latency and shrinking the size of entire data centers.

Tesla, under Elon Musk, experimented with similar concepts in its Dojo project. Though discontinued internally, the approach lives on in ventures like DensityAI.

Lam Research, a major supplier of fabrication equipment, has advanced multi-column electron-beam lithography – through its spinout, Multibeam Corp. – offering manufacturers a pathway to inscribe far larger wafers, bypassing the reticle barrier.

These developments suggest the microchip's reign may soon cede ground to architectures that are dramatically different in both form and function. As wafer-scale integration and new lithographic techniques mature, the possibility of "data centers-in-a-box" becomes tangible, challenging the economic and technological status quo that has dominated digital infrastructure for generations.

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So to sum up… there are other technologies being investigated but dunno if they’ll become viable…

Thanks for this valuable insight…
 
How does this help anything? Yes, you can get more transistors on a chip the bigger you make it. If you look at Nvidia, that's what they've been doing for the most part for the last 10 years. Keep throwing more transistors and Compute Units to make it more powerful. Does it reduce power? How easy is it to cool? Packaging and external support components needed to bring it all together? While this may have it's place, I don't see it taking over HPC system anytime soon. Not to mention, the one size fits all result of an entire wafer is hardly going to replace the current model with the ability to chose what fits your needs.
 
The future of the silicon chip can only go down a few paths...

1. New materials and efficiencies
2. Hybrid models using organic materials
3. Something else.. 🤔
 
It's a neat idea to place memory in the wafer. If RAM and CPU could be combined, or rather, if a CPU basically had one giant pool of memory the size of RAM but as fast as say L4 cache, then that would be incredible. Not sure that's what memory in wafer means per se though, but 7000 times the bandwidth sounds promising at least.

3D (stacked) chips also sounds like a way forward, since anything wafer scale sounds like a low yield endeavor.

I wonder if the push towards larger wafers will reignite the efforts towards mass adoption of the 450mm wafer (from the current 300mm).
 
No. Transistors will adopt new topology, and chips will use a combination of different processes in 3D designs. At some point, we will transition to graphene or something similar.
 
Does it reduce power?
Paths within chip or wafer are much shorter than paths to memory outside chip.
That allows to use much to work at higher frequency with lower latency and less energy.

How easy is it to cool?
Even its more effective ... its HUGE.
So it needs massive cooling system.
NVL-72 needs a massive cooling system too (2/3 of the rack are for cooling).

Waffer scale may have lower yield than chiplets.
But using of 3D design its possible to do at the wafer scale the simplier logic and memory on older less expensive process and the computing part as chiplets.
Combining massive memory bandwidth at lower power and massive compute power without scarificing (too much of) yield.
 
So to sum up… there are other technologies being investigated but dunno if they’ll become viable…

Thanks for this valuable insight…
And if they become viable there will be a few decades of transition in which the savage capitalism will milk all the possible money out of these new tech endeavors, therefore it will not be viable for the most people, so they will be used only at the high level which will not deliver the necessary money to spread it globally fast enough.

To sum it up - we are looking at around a few decades to have an answer. For example look at the so-called quantum computing...it tries for so long but doesn't quite manage.
 
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