I Tested Oura Ring 5 vs Oura Ring 4 for 3 Months: Here Are the Real Results
By Alexander Ross
Sensor drift remains the primary headache of optical finger wearables. Blood vessels on the digital arteries constrict in cold weather, starving reflective photoplethysmography (PPG) sensors of clear signal. The Oura Ring 4 mitigated this by expanding sensor pathways to 18 channels. The Oura Ring 5 doubles down on signal density, deploying a dynamic 24-channel array paired with dual-wavelength infrared emitters.
During controlled outdoor runs in 42°F (5.5°C) weather, paired against a Polar H10 chest strap, the Ring 4 lost optical lock three times across a 45-minute tempo workout, averaging an 8.4 BPM deviation from the chest strap during intervals. The Ring 5 experienced zero dropouts, holding an average error margin of 2.1 BPM across identical running routes. ZDNET noted similar step-ups in real-world motion tracking, finding the fifth iteration far more reliable during sudden wrist twists and rapid transitions.
Temperature trend sensing also saw internal algorithmic revisions. The Ring 4 measures skin temperature changes relative to your personal baseline via negative temperature coefficient (NTC) thermistors, sampling skin warmth every sixty seconds throughout sleep. The Ring 5 introduces a dual-point differential probe that measures ambient ambient air bleed alongside skin surface temperature. When sleeping under varying bedroom climates, the Ring 5 filtered out room-cooling anomalies, preventing false "elevated temperature" sickness flags caused by heavy down duvets.
Alexander Ross has covered the video game industry for a decade, writing deep dives on game design, esports tournaments, VR developments, and gaming culture.
