7-Zip Benchmark Rating and CPU Usage Explained

The built-in benchmark feature in 7-Zip is a widely used utility for evaluating processor stability, multithreading capability, and memory subsystem performance. When executing this test, the interface reports two critical metrics for both compression and decompression: the Usage percentage and the Rating measured in MIPS. This guide breaks down what these specific values represent, how they reflect your system’s hardware behavior, and how to interpret their results.

What the Usage Percentage Represents

The "Usage" percentage in the 7-Zip benchmark reflects the ratio of total CPU time consumed to the elapsed wall-clock time. Rather than capping at 100% like standard system monitors, 7-Zip scales this figure based on thread utilization:

• Single-Core Scaling: A value of 100% represents the full computational capacity of a single CPU core or logical thread.
• Multi-Core Scaling: If you run the benchmark across multiple threads, the percentage increases linearly. For example, if you run the test on an 8-thread configuration and the Usage displays 780%, it indicates that roughly 7.8 processor threads are actively engaged in processing data without idling.
• Hardware Bottlenecks: A lower-than-expected Usage percentage during testing usually points to system bottlenecks outside the core processor logic. In compression tasks, memory bandwidth limitations or high RAM latency often cause processor threads to stall while waiting for data, resulting in lower total CPU usage.

What the Rating (MIPS) Represents

The "Rating" column measures data throughput expressed in MIPS, which stands for Millions of Instructions Per Second. This value quantifies how many operations the processor completes relative to an internal reference baseline designed by the 7-Zip algorithm.

The benchmark divides this metric into two primary categories:

• Compressing Rating: This test heavily exercises the processor's data-matching logic and cache hierarchy. Because compression involves large lookup tables and frequent branch predictions, the Compressing Rating depends significantly on memory latency, RAM bandwidth, and the size of the CPU's L2 and L3 caches.
• Decompressing Rating: This test uses a simpler, stream-based algorithm that places virtually no strain on system memory. Instead, it relies almost entirely on the processor's integer execution units and instruction pipeline efficiency. Consequently, the Decompressing Rating reflects raw CPU architectural performance and clock speeds.

Understanding "Rating / Usage" and "Total Rating"

To provide a clearer picture of architectural efficiency, 7-Zip also calculates the Rating / Usage metric. This value divides the total MIPS rating by the Usage percentage, effectively demonstrating single-core instruction efficiency independent of core count. A higher Rating / Usage indicates that each individual thread is performing more work per cycle.

Finally, the Total Rating at the bottom of the window averages the compression and decompression metrics. This provides a balanced single-score indicator of overall processor capability across both memory-dependent and compute-bound workloads.