# Subnormal floating-point numbers are expensive... on Intel processors

DevFeed: [Subnormal floating-point numbers are expensive... on Intel processors](<https://devfeed.tech/articles/subnormal-floating-point-numbers-are-expensive-on-intel-processors-29431.md>)

Original publisher: [Read original article](<https://lemire.me/blog/2026/09/15/subnormal-floating-point-numbers-are-expensive-on-intel-processors/>)

Author: Daniel Lemire

Published: 2026-09-15T12:54:32Z

Content type: article

Language: en

Sources: [Daniel Lemire](<https://devfeed.tech/sources/daniel-lemire.md>)

Topics: [floating-point](<https://devfeed.tech/topics/floating-point.md>), [Benchmark](<https://devfeed.tech/topics/benchmark.md>), [intel](<https://devfeed.tech/topics/intel.md>), [C++](<https://devfeed.tech/topics/c-plus-plus.md>), [Cache](<https://devfeed.tech/topics/cache.md>)

Tags: [benchmark](<https://devfeed.tech/tags/benchmark.md>), [c-plus-plus](<https://devfeed.tech/tags/c-plus-plus.md>), [floating-point](<https://devfeed.tech/tags/floating-point.md>), [intel](<https://devfeed.tech/tags/intel.md>), [linux](<https://devfeed.tech/tags/linux.md>), [numbers](<https://devfeed.tech/tags/numbers.md>), [performance](<https://devfeed.tech/tags/performance.md>), [processors](<https://devfeed.tech/tags/processors.md>)

## AI overview

This article benchmarks the performance cost of IEEE subnormal floating-point values across Intel, AMD, Arm, and Apple processors. It reports that Intel multiplications involving subnormals can be about 45 to 50 times slower than normal multiplications, while additions and subtractions remain at full speed. AMD Zen 5 performs much better in the tested workloads.

## Source excerpt

We represent floating-point numbers using the IEEE standard. For very small numbers, the standard uses special subnormal numbers. Unfortunately, they have a reputation of making operations slow. Thus video game programmers and machine learning specialists sometimes avoid computing with subnormal numbers for performance. How slow are they? Let me measure. I wrote a small C++ ... Continue reading Subnormal floating-point numbers are expensive... on Intel processors