AMD’s Ryzen 7 9800X3D processor has been a gaming giant since its launch, and a recent teardown by Tom Wassick reveals that a significant portion of the chip is dummy silicon for structural integrity. The findings suggest that only a small part of the 40-45µm thick package consists of actual SRAM and compute die materials.
The Ryzen 7 9800X3D’s design features a stacked architecture, with the L3 SRAM cache chiplet below the heat-generating CCD. This setup allows for higher clock speeds by providing more thermal headroom. However, AMD has never disclosed the details of its stacking methodology.
The report also states that both the CCD and 3D V-Cache chiplets are thinned down to sub-10µm levels to expose the TSVs for hybrid bonding. The total SRAM and CCD package is only 20µm thick if excluding interconnects, but AMD has added a bulky layer of dummy silicon at the top and bottom to provide structural support.
According to Tom Wassick’s findings, 93% of the total stack comprises just dummy silicon, leaving only 7% for actual die materials. The coating between the layers is thinner in some areas than others, allowing for better thermal performance. A Scanning Electron Microscope is needed to further inspect the chip and answer several remaining questions.
Despite losing its gaming throne to AMD, Intel has no plans to counter AMD’s 3D V-Cache technology in the mainstream segment. However, AMD is expected to announce new Ryzen models with 12-core and 16-core processors at CES next month.
Source: https://www.tomshardware.com/pc-components/cpus/amd-3d-v-cache-teardown-suggests-the-majority-of-the-ryzen-7-9800x3d-is-occupied-by-dummy-silicon