Filing volume has been declining for years rather than growing. Filings peaked at 34 in 2017, had fallen to 12 by the 2022 midpoint, and sit at only 2 in the most recent partial year. Publication lag of roughly 18 months means the very latest years will always look artificially thin, but the multi-year decline from peak to midpoint predates that effect and reflects a genuine slowdown in new filing activity in this specific claim space.

The dataset shows concentration among a small number of assignees rather than a single dominant leader, with names like Intel Corporation, Advanced Micro Devices, Inc. (AMD), International Business Machines Corporation (IBM), QUALCOMM Incorporated and Apple Inc. appearing repeatedly across the corpus. Recent-year momentum, however, is thin across nearly all of them — only Apple Inc. shows an active filing in the latest tracked year. The strongest documented collaboration is the internal pairing between Advanced Micro Devices, Inc. (AMD) and its ATI Technologies ULC unit, which co-files far more often than any other assignee pair in the data.

Citation counts inside any searched patent corpus accumulate over time, so older filings simply have had longer to be cited by later ones — this is a known bias, not evidence that the field stopped innovating. The top-cited records here cover single-chip multiprocessing architecture and improved data-stream prefetching, both foundational mechanisms that later cache hierarchy patents had to reference or design around. Treat high citation counts as a measure of influence on subsequent filings, not as a signal of which patents matter most today.

US10606752B2, assigned to Samsung Electronics, covers a coordinated cache management policy across an exclusive L1/L2/L3 hierarchy that filters data by reuse probability and tracks demand-request reuse separately from prefetch-request reuse. It blocks designs that coordinate block replacement across multiple cache levels using that specific reuse-probability filtering and separate-tracking approach. It does not block cache management schemes that use a different signal for prioritisation or that operate on an inclusive rather than exclusive hierarchy — those are the more likely design-around paths.

The clearest under-claimed territory sits at the edges of the core G06F classification, where cache hierarchy mechanics overlap with image data processing, networked data transmission and AI model computation — each of these adjacent IPC subclasses carries only a handful of records against the 526 in the core class. Within the core mechanism categories themselves, prefetch-aware exclusive-cache eviction and cross-tier coherence filtering by reuse probability show comparatively less dense claim coverage than general replacement-policy or coherence-protocol filings. Any new filing there should still be checked against the most-cited records first, since those cover the closest adjacent mechanisms.