# Investigation: Identical Servers, Different Performance

DevFeed: [Investigation: Identical Servers, Different Performance](<https://devfeed.tech/articles/investigation-identical-servers-different-performance-20438.md>)

Original publisher: [Read original article](<https://vinted.engineering//2025/07/15/clocksource-performance/>)

Author: Simonas Rupšys

Published: 2025-07-15T00:00:00Z

Content type: article

Language: en

Sources: [Vinted](<https://devfeed.tech/sources/vinted.md>)

Topics: [Redis](<https://devfeed.tech/topics/redis.md>), [Latency](<https://devfeed.tech/topics/latency.md>), [Linux](<https://devfeed.tech/topics/linux.md>), [Benchmark](<https://devfeed.tech/topics/benchmark.md>), [cpu](<https://devfeed.tech/topics/cpu.md>), [Kernel](<https://devfeed.tech/topics/kernel.md>), [servers](<https://devfeed.tech/topics/servers.md>)

Tags: [benchmark](<https://devfeed.tech/tags/benchmark.md>), [cpu](<https://devfeed.tech/tags/cpu.md>), [hardware](<https://devfeed.tech/tags/hardware.md>), [kernel](<https://devfeed.tech/tags/kernel.md>), [latency](<https://devfeed.tech/tags/latency.md>), [linux](<https://devfeed.tech/tags/linux.md>), [performance](<https://devfeed.tech/tags/performance.md>), [redis](<https://devfeed.tech/tags/redis.md>), [servers](<https://devfeed.tech/tags/servers.md>), [technical](<https://devfeed.tech/tags/technical.md>)

## AI overview

The article investigates inconsistent Redis performance across otherwise identical servers. It finds that servers using the slower HPET Linux clocksource instead of TSC had higher Redis latency and CPU usage, and it explains how to detect and change the clocksource and prevent unintended changes.

## Source excerpt

Inconsistent Redis performance was observed across a fleet of otherwise identical servers. After investigation, we discovered that differences in Linux system clocksource settings - specifically, servers running the slower HPET clocksource instead of the default TSC - led to significant increases in Redis latency and CPU usage.