Garmin Fenix 9 Pro – GPS Accuracy
The Fenix 9 Pro scored 79% overall in my standard 10-mile GNSS accuracy test, against 92% for the Forerunner 970 on 5 Nov 2025 (here’s the overall test methodology). The score split into 90% on easy sections, 81% on medium sections and 63% on difficult sections. I had high expectations going in, since the tests I’ve already run on this watch have been good.
Garmin may have a new GNSS chipset, though that seems unlikely. What has apparently changed is how it handles GNSS constellations: it no longer appears to use Russia’s less accurate GLONASS system. I assumed a change like that would have been rigorously tested and would improve things, not worsen them.
There were several moments of imprecision in the test:
- the route showed on the wrong side of the road during an easy section
- it bounced off a nearby tall building, a multipath error
- it struggled approaching a tall building near a 50m tunnel
- a tricky section produced a parallel track rather than the real route
Re-positioning after a signal loss took about 10m. My best guess is that the accelerometer-adjusted position in the tunnel drifted off, and the algorithm smoothed the correction back to the last known position, though the exact cause is unconfirmed.
Fenix 9 Pro has a new antenna construction and a titanium case. Either could affect reception quality. Dropping GLONASS could also be the cause, though a tweaked algorithm looks more likely.
It wasn’t the conditions on the day. The other device on the test, the Suunto Run 2, scored 85% after previously scoring 90%, both times worn on the right wrist, the worst side for this test.
Here’s what I mean
Last Updated on 14 September 2026 by the5krunner
My favourite kit and nutrition
- Garmin Fenix 9 Pro — I’ve just bought one.
- Injinji – Runners protect your toes. Avoid discomfort and minor injury. Run more. Run faster. I use them.
- Garmin 90-degree charging adapter — A small keyring adapter you can use anywhere. Essential when away. I use one.
- Garmin charging puck — the fastest and most reliable way to top up your Garmin before a session. I use one.
- Ravemen FR300 — Front light that mounts directly under your Garmin or Wahoo head unit. Keeps your bars clean and your beam pointed where it matters. I use one.
- Body Glide – The blue anti-chafe stick that all swimmers and many runners use. I use it.
- Maurten — The race nutrition trusted by elite athletes. Gels and drink mixes engineered to be easy on the stomach. I use them.
- Garmin Varia RTL515 — A radar rear light that alerts you to vehicles approaching from behind. Pairs with your Edge or Wahoo. I use this model.
- Favero Assioma Pro RS2 — The power-meter pedals most serious cyclists choose. Accurate, easy to move between bikes. I use this model.
- Garmin Forerunner 970 — A serious choice for a pro-grade triathlon watch. I use this.
- Polar H10 — My daily driver for accurate, waking HRV readings.
- Wahoo ELEMNT Roam 3 — The bike computer that has the feature Garmin lacks: usability. I use mine on most rides.
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tfk is the founder and author of the5krunner, an independent endurance sports technology publication. With 20 years of hands-on testing of GPS watches and wearables, and competing in triathlons at an international age-group level, tfk provides in-depth expert analysis of fitness technology for serious athletes and endurance sport competitors. ID
Is this in SatIQ mode or all band max accuracy?
per second max. as per the methodology doc
So the Cheetah 2 ultra is better: 85% (Easy (90%), Medium (81%), and Hard (81%)).
when things are close like 83 vs 85 then i would say it is NOT any kind of proof. but 79 vs 90 is a sign that one is almost certainly better.
n=1 of course.