← Back to Library

Huawei ascend production ramp: Die banks, tsmc continued production, hbm is the bottleneck

Dylan Patel doesn't just track chip shipments; he maps the invisible fault lines of a global technological cold war. In this analysis, the most startling claim isn't that China is building its own AI hardware, but that the United States' own export controls may have inadvertently created a massive, temporary reservoir of foreign-made silicon that will keep Beijing's AI ambitions alive for another two years. This is not a story of inevitable American victory, but of a complex, lagging regulatory game where stockpiles and loopholes currently outweigh policy intent.

The Strategic Reservoir

Patel frames the current moment as a precarious equilibrium where compute is the "lifeblood of AI" and the United States holds a commanding lead with "more than 70% of the worlds deployed FLOPs." Yet, he argues that the administration's strategy of "Limiting your competitor nation state from compute, which will limit them from intelligence" has produced an ironic side effect: it forced Chinese firms to adapt and stockpile. The core of Patel's argument rests on the existence of a "Die Bank"—a massive inventory of logic chips fabricated by TSMC before restrictions fully took hold.

Huawei ascend production ramp: Die banks, tsmc continued production, hbm is the bottleneck

He writes, "It is specifically this 'Die Bank' of foreign chips from TSMC that gets them through 2024 and 2025. Without this Die Bank, Huawei's Ascend production numbers would be much lower." This evidence is crucial because it shifts the narrative from China's immediate inability to produce to a calculated delay in their domestic manufacturing ramp. Patel suggests that the administration's timeline for enforcement was too predictable, allowing for a rush to build inventory. "The U.S. routinely exempts Japanese and Dutch companies from its equipment export controls... The problem, however, is that when new export controls come out, Japan and the Netherlands do not immediately follow." This lag creates a window where Chinese entities can "rush order years' worth of equipment to stockpile."

Critics might argue that focusing on stockpiles underestimates the long-term degradation of Chinese capabilities once these reserves are exhausted. However, Patel's data on the sheer volume of these reserves suggests the timeline for exhaustion is further out than many policymakers assume.

"Beijing plans for the long term and knows it must secure its own domestic compute destiny."

The Vertical Integration Gamble

The commentary then pivots to Huawei, which Patel identifies as the central actor in China's quest for sovereignty. He notes that "China loves national champions... and in it's characteristic capitalism, tends to funnel resources to a few national champions." Today, that champion is Huawei, which is attempting to replicate the entire semiconductor stack, from design to fabrication tools. Patel highlights the scale of this ambition, noting that Huawei has become the "4th largest WFE customer globally in two years" and is investing billions to build its own fabs.

The author argues that this vertical integration is a direct response to the "irony" of the situation: "In the 2010s China kicked out Google to enforce its Great Firewall and foster its domestic industry, this time the US government is withholding hardware technology so they cannot seize the lead in AI." Patel's analysis of Huawei's production numbers is particularly compelling. He estimates that Huawei shipped 507,000 Ascend units in 2024 and expects that number to rise to 805,000 this year, largely fueled by the TSMC inventory. He asserts that "SMIC, however, now has more than enough capacity to produce meaningful volumes of chips," suggesting that the domestic foundry is no longer the primary bottleneck.

This framing is effective because it moves beyond the binary of "can they make chips?" to "how many can they make and for how long?" Patel's data suggests that even with lower yields than Western competitors, the sheer volume of capacity allocation at SMIC could support millions of chips annually. "If 100% of capacity was allocated to Ascend die, their production capability would be in the tens of millions per year." This challenges the prevailing narrative that sanctions have effectively halted China's AI progress.

The Memory Bottleneck

Despite the optimism around logic chips, Patel identifies a critical vulnerability in China's supply chain: High Bandwidth Memory (HBM). He argues that while logic die production is ramping, memory remains the "key constraint." The analysis details how Samsung, anticipating the restrictions, exported a staggering amount of HBM to China in the final quarter before enforcement. "Samsung exported as much as possible to China in that one quarter... This comprises the majority of China's HBM."

Patel writes, "We expect that China will be bottlenecked by HBM by the end of the year as they run out of foreign HBM." This is a pivotal distinction. The administration's recent "Action Plan" to tighten controls on semiconductor subsystems is noted as a positive step, but Patel points out that "many subsystem firms that supply western players such as VAT Group in countries like Switzerland without controls will not be stopped from shipping critical chambers to China." The argument here is that while the logic chip bottleneck may be solved through domestic production and stockpiles, the memory bottleneck is a harder nut to crack without tighter international coordination, particularly with South Korea.

A counterargument worth considering is whether China's domestic memory manufacturers, such as CXMT, can scale fast enough to fill the gap before the foreign stockpile runs dry. Patel acknowledges this risk but maintains that the current reliance on foreign HBM is a significant strategic weakness.

"HBM production is the bottleneck. China does too, which is why they have asked US officials to relax controls on HBM as part of the recent trade talks."

Bottom Line

Patel's strongest contribution is his granular dissection of the "Die Bank," revealing that the impact of US sanctions is not immediate but deferred, creating a dangerous illusion of containment while China builds its own infrastructure. The argument's greatest vulnerability lies in its reliance on yield improvements at SMIC and the assumption that domestic HBM production cannot scale quickly enough to replace the lost foreign supply. Readers should watch for the next six months: if the TSMC inventory depletes before Huawei's domestic memory capabilities mature, the bottleneck will shift from a manageable constraint to a critical failure point for China's AI ambitions.

Sources

Huawei ascend production ramp: Die banks, tsmc continued production, hbm is the bottleneck

by Dylan Patel · SemiAnalysis · Read full article

Compute is the lifeblood of AI. He who controls the spice controls the universe the compute will control the production of tokens and reap the benefits of AI. Without compute you do not have a seat at the table. The United States technology community is all in on compute and AI as the next platform and is now adding compute at a staggering pace.

There is competition, and it not only comes from companies but from countries, and the US government has placed a series of export controls to limit China’s rising compute. Today the US controls and is the undisputed leader in compute with more than 70% of the worlds deployed FLOPs. One way to stay ahead is to keep going full steam while hindering your competition. Limiting your competitor nation state from compute, which will limit them from intelligence, is the current policy to stay ahead in the AI race.

These moves have led to backlash, including with China cutting rare earth minerals and magnets off from the US. Secretary of Commerce Howard Lutnick says the resumption of Nvidia GPU sales to China were required to restart China's shipments of their linchpin supply chain materials.

But constraints have also led to adaptation, and Chinese companies have adapted. High batch sizes and disaggregated serving are but two examples. Despite advances, in the case of DeepSeek, most of their tokens are still inferenced on western hardware. We wrote about this dynamic in our recent DeepSeek debrief. Training of DeepSeek's next generation model was also delayed by the use of Huawei chips, as we also said in the debrief.

This is not a stable equilibrium. There are always moving pieces in the race for intelligence. Beijing plans for the long term and knows it must secure its own domestic compute destiny. There is an irony: in the 2010s China kicked out Google to enforce its Great Firewall and foster its domestic industry, this time the US government is withholding hardware technology so they cannot seize the lead in AI.

We believe that at China’s core, they want to control not only its internet and AI, but the hardware that supports it. From silicon to tokens, China seeks sovereignty over every layer of the stack, and given recent history will never want to be beholden to foreign powers. Enter Huawei.

China loves national champions, and in it’s characteristic capitalism, tends to funnel ...