AI Server Makers are Under Strain, CASCI Data Shows
[CASCI] Signs of deceleration at the assembly end, even as chip and component revenue growth accelerates at the start of the supply chain
CASCI Composite June 2026 Highlights:
140.9 points, driven by rapid uptick in chipmaking
+1.4 pts, rising for 10th straight month
Divergence emerging between strong upstream and weaker downstream tiers
This month’s CASCI report was delayed by a typhoon which swept across Taiwan and shut businesses for two days. There’s no indication that operations across the supply chain were affected, but it’s another reminder of the resilience needed when doing business in Taiwan.
CASCI is a proprietary index developed by Culpium based on real data. It’s now one of the industry’s most-watched metrics.
Culpium will go paywalled in coming months. The price will rise 40% ($100→$140/yr) one week after the paywall begins. Pledge now to lock in the lower rate, but subscribe first if you’re new here. Thanks.
The Composite View
For the first time this year a clear divergence is emerging between upstream and downstream tiers of the AI compute supply chain.
Although there continues to be growth across all tiers — the sector is still broadly strong — CASCI data shows acceleration at the top and deceleration at the bottom.
Making and selling a chip doesn’t guarantee demand exists for that chip to be assembled into a final AI device such as a server. This is a warning sign that inventory may start piling up if server assemblers cannot digest the supply of components quickly enough.
Observers should watch announcements from major server buyers for signs that they’re pausing the incremental increases in capex forecast that we experienced over the past few quarters.
Upstream
TSMC’s massive growth (58% in USD terms for June) is not isolated. Acceleration among upstream AI compute suppliers was seen across the entire passive and semiconductor components sector. Chip designers, chip manufacturers, and makers of upstream parts are receiving and fulfilling orders at a continuously faster rate.
Mid-stream
There’s solid growth at the mid-stream of the AI compute supply chain with the largest pace of acceleration in six months.
However, there’s some divergence to be seen. Mechanical parts for AI servers, particularly metal components, used at the PCB and rack level are experiencing unprecedented growth and upward momentum. This is tempered by slightly milder growth in other areas, notably in cooling systems and related parts.
That said, momentum in the mid-stream returned in June, an indication that acceleration may continue for a few months.
Downstream
Server assembly is at the weakest pace of growth in at least six months, even after accounting for seasonality. Growth decelerated for a second straight month and a continued slowdown could push this tier to the weakest in more than a year.
There’s an important caveat we need to be aware of when examining this development. Many assemblers have moved more of their components to a consignment model. Rather than buy and on-sell parts, they’re letting clients procure these parts and ship them to the assembler’s factory. This can crimp top-line growth and impact gross margins. However, Culpium analysis indicates this shift only partially explains the deceleration.
While there remains growth in output of AI servers, CASCI data shows manufacturing momentum at the end of the supply chain is starting to weaken.
Capacity
Construction of factories and installation of equipment decelerated in June, falling from recent highs. Data indicates this may be a pause in the construction phase as opposed to a slowdown or cancelation of equipment orders.
CASCI is a weighted index tracking revenue of Taiwanese companies in the AI compute supply chain. Taiwanese companies make up the majority of upstream, mid-stream, and downstream of AI server manufacturing
Culpium and its monthly CASCI report are free for now. But a paywall is coming, and a price rise soon after. Lock in a discount now by subscribing and then pledging. Thanks.
Notes for Editors & Analysts:
CASCI is published monthly by Culpium as a service to readers.
Media and analysts are welcome to cite CASCI or the Culpium AI Supply Chain index, with attribution and link. For example, “AI server manufacturing remains strong, according to the latest CASCI report from Culpium.”
Data graphics may be reproduced with credit.
Entire contents of Culpium or CASCI reports may not be reproduced unless a publishing fee is paid.