Overview
ARM MTE has no universal performance tax: cost depends on tag checks, fault mode, core design, workload, allocator, kernel, and measurement boundary. The series moves from MTE’s probabilistic 16-byte contract to silicon and full-stack bottlenecks, then compares security uses and gives a measurement-first adoption framework. Averages cannot replace tail analysis or a fair baseline.
Learning outcomes
- ARM MTE has no universal performance tax; cost varies by mode, core, workload, and software stack.
- Large slowdowns can arise from diagnosable implementation or integration limits, not from tagging alone.
- MTE’s 4-bit tags and 16-byte granules provide probabilistic, not complete, memory-safety defense.
- Adoption should compare the complete security alternative and measure tails on the system that will ship.
Keywords
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PlansFAQ
Why does ARM MTE have no single performance cost?
Because the measured cost depends on the fault mode, core implementation, memory pattern, allocator, kernel policy, baseline, and deployment topology.
What does ARM MTE actually protect?
ARM MTE checks 4-bit pointer and memory tags on 16-byte granules, helping detect many temporal and spatial errors but not proving complete memory safety.
Is ASYNC ARM MTE always cheaper than SYNC?
No. ASYNC defers fault handling and reduces some ordering pressure, but tag checks still consume hardware resources and can bottleneck on particular cores and workloads.
How should a team evaluate ARM MTE before production?
Define the security objective and fair baseline, then measure the shipping mode, cores, workload, allocator, kernel, topology, and performance tail while preserving coverage limits.