How does LINQ affect CPU cache efficiency in high-performance applications?

LINQ can reduce CPU cache efficiency due to iterator indirection and scattered memory access patterns.

LINQ introduces abstraction layers such as iterators, delegates, and deferred execution pipelines. These abstractions often break data locality, which is critical for CPU cache performance. In contrast, manual loops operate on contiguous memory with predictable access patterns, improving cache hits. In high-performance workloads, LINQ’s iterator chaining may result in cache misses and branch misprediction penalties, especially when processing large datasets.