Garmin fenix 5X vs Suunto: GPS Track Comparison

Always a question – if not the question – with the sports/outdoor watches: So, which is better?

The answer may actually not be as clear as many would like it to be. Even when it comes to such simple things as measuring a distance covered, there are different approaches leading to different results.

All the more reason to show by examples, what is recorded and how, by the Garmin fenix 5X and different Suunto models…

GPS-Track Recordings, Garmin vs. Suunto

The major function of GPS-equipped sports watches, aside from navigation: Of course, the measurement and recording of the tracks taken.

Example 1: 25k, Flat Area, Fields and Forest

First of all, a look at the map. A Google MyMap with the tracks of a Garmin fenix 5X (in blue) and a Suunto Spartan Ultra (in yellow), worn on opposite wrists.

The area here is flat with just a few hills, mainly open but with some forest. Close to ideal conditions for GPS.

Here, the influence of the position of the respective watch on the one wrist or the other seems the largest factor; there is the usual offset one gets from that.

It seems to also be the case that the fenix 5X records rather more points, resulting (here) in the wider look of tight curves I ran, whereas the Spartan discounts some of those points close by each other.

Screenshot aus der oben eingebetteten Landkarte mit Vergleichs-Tracks, fenix 5X bzw. Spartan Ultra
Screenshot from the Google (My)Map embedded above. I did run those hooks in the upper right; the fenix 5X shows especially the first one as wider than the Spartan; I’d say I pretty much just ran to-and-back. The differences between the two tracks when entering the forest are pretty typical for GPS problems in such conditions, and with watches worn on opposite wrists.

The fenix 5X recorded:

  • 25.34 km distance
  • 426 m ascent, 427 m descent

The Spartan Ultra:

  • 25.46 km
  • 370 m ascent, 381 descent

Example 2: Italian Cities

A very special challenge for GPS are cities, especially when they are like old Italian towns with their tight roads… GLONASS might have helped here, actually, but I always “only” used GPS by itself.

I put all the comparison tracks into the one map above, so you’ll have to zoom in and choose which tracks you want to see: the morning run in Rome, the sightseeing walk in Florence, or the morning run in Florence…

There are also a few details I want to point out explicitly, though:

Rome, Around the Vatican and On

Screenshot of the Google (My)Maps map above, Rome morning run
Screenshot of the Google (My)Maps map above, Rome morning run

All in all, not so bad. Both watches had their issues; one shouldn’t look at tracks like that with too great a zoom, given all the factors that can disturb them, but it is obvious where I went and difficult to say if the one or the other piece of equipment really worked better here.

The section I find particularly telling is that between Faro degli Italiania d’Argentina and Chiesa di Sant’ Onofrio al Gianicolo, along the section more to the east, going from South back North.

Looking at this section a bit more closely (see below), one can again tell the influence of which wrist which watch was worn.

There is also that issue of the fenix 5X apparently recording more points, even when there is little movement between them, again: The bit south of Faro degli Italiani d’Argentina, at which I (seem to have) moved back and forth quite a bit, is where I mainly stood and recorded the sunrise.

Farther north from that, where things look similarly convoluted again?

That’s where I turned on navigation on the fenix 5X to let it guide me back. That showed me on the roads I was on quite well (which one might not expect from just looking at the tracks now) and guided me well, too. Where the course I needed to take had many curves (right there at the beginning), there were also some issues, though, as I mentioned in the post about the potential downsides of the navigation.

Right there at the beginning, that is, it was not entirely clear where the navigation wanted to guide me…

Detail from the Rome morning run map
Detail from the Rome morning run map
  • f5x: 8.41 km, 136 m ascent, 138 m descent
  • SSU: 8.07 km, 116 m ascent, 126 m descent

(If you’d like to see what running here looked like, by the way: There’s a video of it here.)

Florence, On a Walk

This recording shows very clearly how the fenix 5X definitely applies less of a filter than the Spartan Ultra and thus gets in trouble when there is only slow movement and probably GPS signals that get reflected.

Right at the beginning of my walk (in the Southwest), the fenix 5X suddenly shows me in a park I never went to; it must have received a wrong signal there.

At Santa Maria del Fiore (the Duomo) in the North(east) of the walk, I spent quite some time walking to-and-fro to take pictures, and the fenix recorded many more and farther-apart points than the Spartan Ultra.

It is also quite visible how difficult the situation in Florence’s small and tight streets is for any GPS device; the tracks recorded by both watches show quite some jumps…

Screenshot from the Google (My) Maps above, Florence sightseeing hike
Screenshot from the Google (My) Maps above, Florence sightseeing hike
  • f5x: 5.49 km
  • SSU: 4.72 km

Florence, Running

The image painted by this morning run in Florence, mainly along pretty much the same roads as on the walk the day before (and in the map above), is pretty interesting: The pace was rather higher, I should hope, there was less moving around in the same place – and the recording looks a whole lot better.

Screenshot from the Google (My)Maps map above, showing the early morning run in Florence
Screenshot from the Google (My)Maps map above, showing the early morning run in Florence

It is all more than just a lot better when looking at the distance recorded (especially as compared to the distances recorded before, on the walk)…

  • f5X: 5.77 km
  • SSU: 5.80 km

Reflected signals or otherwise bad reception had their effect here, too – and again seem to have greater effect on the fenix 5X than on the Spartan Ultra.

Example 3: Into the Mountains

I couldn’t leave out my favorite mountain trails for GPS watch tests, as I already mentioned in my video about the navigation and used to show how that works.

Now for the comparison data from that, too – which are a tad more difficult to interpret as I was run-walking this trail with a total of four(!) watches 😉

So, this was with a Garmin fenix 5X and a Suunto Ambit3 Peak on my left arm, Suunto Spartan Ultra and Spartan Sport WHR Baro on my right arm, all a few centimeters of separation from each other to, hopefully, avoid ‘measuring’ interferences between them.

Have fun trying to determine which was more exact.

But. Here, too, it looks quite certain that the Garmin filters less or is more sensitive; it shows more track points as different positions which the Suunto watches seem to discard as measurement errors.

And thus… Well, it’s still hard to tell.

It could be that this makes the fenix 5X follow tight curves on such a trail better, but it could also result in it saving more erroneous points.

Screenshot of detail from the Google (My) Maps map above, showing GPS tracks from four different watches at the Sonnsteine trail in Upper Austria
Screenshot of detail from the Google (My) Maps map above, showing GPS tracks from four different watches at the Sonnsteine trail in Upper Austria

What is obvious is that the separation/offset between watches worn on the left/right arm is there; the section right above the “Google MyMaps”-text shows quite nicely, I think, how the Suunto watches filter out points where the Garmin records them, going right-left….

This difference in approach to position recordings has a large influence on the total distance eventually recorded, as already seen in the walk in Florence (which also included more stops):

  • fenix 5X: 8.07 km; 772 m ascent, 807 m descent
  • SSU: 7.13 km; 804 m ascent, 825 m descent
  • SSWHR Baro: 7.61 km; 822 m ascent, 833 m descent
  • Ambit3 Peak: 7.36 km; 765 m ascent, 800 m descent

As is easily seen, there was quite the spread of data recorded. If one believes the altitude profile recorded by the Ambit3 Peak, then the fenix 5X measured ascent/descent very well, the Spartans less so. In terms of distance, though, the fenix 5X disagrees pretty strongly from the Suunto watches, which are at least somewhat more consistent…

(Analyzing the gpx-files via MyGPSFiles made the differences even more clear. There, the tracks give 7.6 km as recorded by the Spartans, 7.7 km per Ambit3 Peak, but 8.6 km on the fenix 5X. The altitude profiles given there, however, only vary between 757 m ascent according to fenix 5X and Ambit3 Peak, 762 m for the WHR Baro and 768 m according to the Spartan Ultra; 790-794 m of descent on fenix 5X, SSU, A3P and 774 m on the WHR Baro.)


Difficult to draw sensible conclusions from that.

The fenix 5X had to fight with erroneous signals on pretty much all my tracks, more so than the Suunto watches, in any case. It also seems to follow a different approach to rates or filtering of location data, so that it tends to record longer distances meandering back and forth more.

If that should be reason to argue that the fenix 5X’s GPS is faulty or be seen as an advantage on meandering mountain trails (if not in cities with tight and curving roads), however, I would not want to be the judge of.

With the map display on the Garmin watch coming into play, the problem (if that’s what it was) also seemed moot: The map typically, whenever I checked it, showed me in the right location…

4 responses

  1. Cato Avatar

    I wonder how results would be if running a shorter route twice altering the same two watches on right and left wrists.

    1. Probably would be telling far less simply because there would be less data, thus fewer chances for screw-ups 😉

      1. Cato Avatar

        I thought differences between the watches would be easier to spot, ruling out left/right wrist issues. But, ofcourse, you could settle for a longer route if you are plagued with to little data. 😀

        1. Now, def too little data, since the fenix was only on loan from Garmin. But, if one just looked at short routes, there would either be nothing (no difference) or jumps if there was anything. And the effect of different approaches to recording that can be seen in the walk in Florence. Statistics like fellrnr does could be more telling, but those are another issue again (to be discussed, at least obliquely, when I finally publish my HR data comparison 😉 )

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