CPUheavy

CPUheavy is a term used in computing to describe workloads or software tasks that are predominantly limited by the performance of the central processing unit (CPU). In such tasks, the rate at which work progresses is primarily determined by CPU execution time rather than by input/output operations or graphics processing units (GPUs).

Characteristics include high CPU utilization, significant instruction per cycle (IPC) requirements, and sensitivity to clock speed, cache locality, and branch prediction. Performance may scale poorly with faster memory or faster disks if the bottleneck remains the CPU. CPUheavy tasks are often single-threaded or only modestly parallel, though multi-core execution can improve throughput when the workload is parallelizable.

Common examples include complex numerical simulations, cryptographic computations, data compression, certain real-time encoding tasks, and some algorithmic processing where the core work is intensive per data unit.

CPUheavy is contrasted with IO-bound workloads, which are limited by disk or network throughput, and GPU-heavy workloads, which rely on graphics processor or accelerator units. Profiling tools (e.g., perf, gprof, valgrind, Intel VTune) help identify CPU-bound sections by measuring CPU time versus wall time, cache misses, and instruction counts.

Optimization strategies emphasize improving CPU efficiency: selecting memory-friendly algorithms, optimizing data locality, enabling compiler optimizations, hand-vectorization using SIMD, and parallelizing workloads using threads or multiprocessing. In some cases, offloading to GPUs or accelerators can mitigate CPU bottlenecks if feasible.

Understanding whether a task is CPUheavy informs system design, capacity planning, and benchmarking. Metrics such as cycles per instruction, throughput in operations per second, and sustained clock efficiency guide comparisons across processors. The concept is a practical counterpart to CPU-bound versus IO-bound discussions in performance engineering.