Suunto 9 GPS Testing: Best GPS at the LGT Alpine Marathon

June 16, 2018. LGT Alpine Marathon in Liechtenstein – with the Suunto 9.

At the starting line, testing-wise: That new Suunto 9, the trusty Ambit3 Peak, and the Suunto GPS TrackPOD.


The race was one of the best I have run so far, in my opinion. That will soon be the topic of a race report and video on my other blog (and YouTube channel).

Here and now, I want to just focus on the technology I had in use.

Inauspicious Beginnings

This almost wouldn’t have worked out fairly.

Some time before the start, I went to check on all the tech.\

Suunto 9: Turn it on, get the fix, get HR. Make sure battery mode is on performance, GPS set to best.

GPS TrackPOD: Turn it on, get the fix.

Ambit3 Peak: Turn it on, see that it is connecting to the HR belt I brought, wait for GPS.


I forgot to sync the Ambit3 Peak with Movescount, so it didn’t have the SGEE file that helps it get GPS satellite fixes faster.
For some reason, great as the view to the sky was, it didn’t want to get a GPS fix for some 15 minutes.

It was still all well before the race start, so in the end, it did get a fix.
Everything had time to get a good number of satellites (probably).


Kilometer past kilometer, it looked like the Suunto 9 recorded a bit more distance than the Ambit3 Peak.

Both were quite close to each other (not even 100 m of difference), though.
Both made it quite clear when some of the kilometer markings were not in the right spots.

Judging by places where the markings looked to be in a good spot (almost everywhere), the Suunto 9 was rather closer to their location, the Ambit3 Peak showed the next kilometer a bit later.

There is, of course, the usual problem with judging such things:
Markings are never perfect but, more importantly, one never runs the ideal line, so some difference is to be expected from that.

Add erroneous GPS recordings, the difference in tracks recorded from left versus right wrist (Suunto 9 vs. Ambit3 Peak, respectively) or left shoulder (GPS TrackPOD), and there should be even more difference.

The Course

The LGT Alpine Marathon in Liechtenstein was the perfect course for performance mode / best GPS testing, though.

Long enough that it matters, over some road in the open and lots of mountain trails and forest tracks, with considerable altitude difference, to boot.

(I will put up a race course description on this here blog.)

Results, Track-Wise

Looking through the tracks, some differences are noticeable.

First of all, this is/was still a GPS firmware that gave the S9 some wiggles in the track it recorded.

Suunto 9 GPS wiggles

Suunto 9 GPS through Vaduz

Several places, the Suunto 9 track also didn’t record the curves quite as nicely as the Ambit3 did… however, as one can often also see from the GPS TrackPOD, these were typically curves to the left, where the offset from the watch having been on my left side mattered rather more.

There are also places where the Suunto 9 recorded me rather more properly than the Ambit3 did, and even instances where the Ambit 3 Peak recorded the track going off to the side in a way that it didn’t, really.

GPS Tracks of Suunto 9 and Ambit 3 Peak (with an issue in the latter)

The usual problem here, too:
We all just love to zoom in as far as possible and give the tracks a hard look – but actually, the map data (and map versus satellite views) is often not good enough for that. What looks perfect in one view is actually off to the side in another.

Zoom out for a more appropriate perspective on it all, and you get what you get from the numbers.

Results, By the Numbers

As much as we like to point to single curves and errors as the outstanding examples of good or bad results, it’s the overall perspective that it is rather more important to judge from.

There is still not enough data for a statistical analysis of differences (and the firmware is still being updated rather heavily), but there is the overall numbers for the whole race, at least:

Official numbers say that this is a marathon distance of 42.195 km with 1870 m of ascent and 720 m of descent.

The much-trusted Ambit3 Peak recorded a

  • total distance of 42.02 km, an
  • ascent of 1876 m and a
  • descent of 719 m
  • (with the lowest altitude at 441 m and the highest at 1778 m).

The GPS Track POD gave a

  • total distance of 41.61 km, an
  • ascent of 1970 m and a
  • descent of 821 m
  • (lowest point at 439 m and highest at 1788 m).

Remember that the altitude-related data here only comes from GPS.

The Suunto 9, finally, recorded a

  • distance of 42.15 km, an
  • ascent of 1872 m and a
  • descent of 716 m
  • (lowest point 432 m, highest point 1779 m).

That’s an 0.3% of difference (126 m) between the Suunto 9 and the Ambit 3 Peak; 2% or 3.5% difference regarding ascent / descent.


Considering that the Suunto 9 is still near the beginning of its firmware development, the Ambit3 Peak at its ultimate, that is more than a nice start.

Next up, the Traunsee Bergmarathon (mountain marathon around the Traunsee lake) with its 75 km and 3500-or-so ascent.

It should work out in performance mode, but I’m thinking I’ll use it to give the Suunto 9’s FusedTrack a good hard look.

If you want to support my work a little while treating yourself to a new Suunto 9, here’s an affiliate link-option for that:

2 responses

  1.  Avatar

    Thanks for the detailed maps!

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