Suunto SPARTAN ULTRA – GPS Tests for accuracy against Edge 820, TomTom Runner Spark 3, Polar V800 and Garmin 920XT

suunto Spartan Ultra - Polar V800 - Garmin 920XT
Polar V800 -Suunto Spartan Ultra – Garmin 920XT

The main purpose of this test was to put my mind to rest about what seems to be great hardware in the Suunto SPARTAN ULTRA using last week’s firmware v1.1.30. Hopefully my GPS test might, or might not, also allay the fears of some AMBIT 3 users contemplating a Suunto upgrade for Christmas.

Backstory: I’ve probably used the SPARTAN for sport for over 30 hours as I write this. Most of my usage is suburban with low buildings but lots of parks and trees and is mostly flat. So I appreciate this is FAR from the rigours that some of you will be putting the SPARTAN through. However I might have a few more watches than you to give you a comparison in relatively like-for-like conditions.

Garmin Edge 820

More thorough testing would look at a large sample size of data points for the repeatability of the results. Indeed we might argue that ACCURACY = REPEATABILITY+TRUENESS+PRECISION. Precision is closeness of resulting points even if wrong, whereas trueness is an accurate average point. We could also look at differing weather condition, tree cover, large building and positional recovery after exiting an obstruction such as a tunnel.

Today’s GPS Tests – all set with best/GLONASS type settings as available

  1. Bike – Slow in traffic and undulating for 60 minutes. TT bike in aero following roads.
    1. Edge 820 – mounted on aerobars
    2. Suunto SPARTAN ULTRA left arm
    3. TomTom Runner 3 / Spark 3 – right arm
    4. Garmin 920XT – back pocket type position, which might have affected accuracy Edit: ULTRATRAC on…which DID affect accuracy…sigh/doh.
    5. Polar V800 – back pocket type position, which might have affected accuracy
  2. Run – 80 minutes endurance. Flat with frequent tree cover following marked tracks
    1. Suunto SPARTAN ULTRA left arm
    2. TomTom Runner 3 / Spark 3 – right arm
    3. Garmin 920XT – back pocket type position, which probably affected accuracy. Edit: ULTRATRAC on…which DID affect accuracy…sigh/doh.
    4. Polar V800 – back pocket type position, which probably affected accuracy
TomTom Runner 3 / Spark 3
Pretty Colours of the TomTom (Adventurer and 2x SPARK shown)

BIKE: Summary Results –  track which overlaid best on a Google map, judged by eye

  1. 2 month old 920XT performed poorly with ULTRATRAC.
  2. The Edge 820 and Spartan ULTRA were neck and neck. The Edge probably just about edged the win (excuse the intended pun).
  3. Surprisingly the TomTom just pipped the renowned accuracy of the V800. As I mentioned above though the position of the V800 likely compromised its performance.

This image is as good as any from the ride

920XT missed the segment entirely
920XT’s ULTRATRAC missed this segment entirely


I would be happy to accept all the performances, except the 920XT’s ULTRATRAC mode.

Total ride recorded was:

Edge 820 (19.63km), TomTom Runner /Spark 3 (19.61km), Garmin 920XT (19.21km by ULTRAC), Suunto SPARTAN ULTRA (19.85km), Polar V800 (19.79km).

RUN: Summary Results

All had autolap on at 1km. They were all beeping within 3 seconds of each other at each km. Bizarrely at 11km I got a very pleasant surprise when they all beeped pretty much simultaneously, some people would pay good money for that experience.

Looking at the Google Map track of all 4 simultaneously was interesting. The ULTRATRAC mode of the 920 was not accurate enough for me except in a ‘sporting emergency’. However all the others basically took it in turns at appearing to be most accurate. Yep, even the TomTom had a go at that! Overall the Suunto Spartan probably *just* about won over the TomTom but, at the same time, the SPARTAN also had me spending the most time in the river, rather than on the towpath.

tomtom-on-track)yellow)-suunto-on-river (blue)
tomtom-on-track (yellow)-suunto-on-river (blue)

Here though Suunto was correct using the pedestrian crossing like a good boy, no doubt he also looked left AND right.


And here Polar Triumphs in Green

polar-triumphs in Green
polar-triumphs in Green

Overall the distances running were: TomTom (13.98), Garmin 920XT (14.14km), Polar V800 (14.07), Suunto SPARTAN ULTRA (14.16). Considering the Garmin was  in ULTRATRAC mode it is surprising that the overall distances is close to the probable winner – the SPARTAN.

Using GPS for instant/current pace ?? – too complicated with 4 watches, sorry. It’s likely they’ll all be rubbish. Actually it’s likely the 920XT would have won as I had a calibrated ANT+ footpod and only the 920XT worked with it    🙂

Super Summary: Today none of them stood out as being perfect and all seemed close to each other’s accuracy. Except the 920XT in ULTRATRAC mode. The rest would have kept me happy. Suunto’s Spartan just won. Edge was a very pleasant surprise. TomTom was unexpectedly good. Polar can be excused for being in my back pocket but was still good.

More Info: If you want someone who has a bit of a thing about GPS accuracy then I think it’s Jonathan at (Sep 2016 – No SPARTAN test yet). He’s your man for running through the same windy valley 100 times to get a statistically large enough sample size. I’m not going to do that (lack of valleys 😉 …and time).

Jonathan found that the most accurate GPS he has tested is the Polar V800 and the Suunto AMBIT3 and he argues that with new technology GPS accuracy has generally seem to FALL over time. Perhaps as accuracy is compromised in favour of other technical factors like battery life and type of antennae? In my rudimentary test for this post I found that THIS TIME the V800 was definitely not the most accurate and, also in contrast to Jonathan’s extensive tests, I found the Polar M400 (one of his worst performing devices) at other times was more than Ok. SO BEFORE YOU LISTEN TO WHAT I SAY OR ANY ONE OTHER PERSON SAYS BASED ON ONE OR TWO ‘TESTS’; REMEMBER THAT WE ARE ALL PROBABLY WRONG!

Where I definitely agree with fellrnr would be that a footpod gives the most accurate running pace figures. And if you are a runner then knowing how fast you run is, errrr, quite important. Clearly a footpod has no idea where you are, so if you are navigating then a holistic measure of accuracy is important.


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4 thoughts on “Suunto SPARTAN ULTRA – GPS Tests for accuracy against Edge 820, TomTom Runner Spark 3, Polar V800 and Garmin 920XT

    1. I look a bit of an idiot normally. More so wearing two watches. Even I know that 4 is too much for my neighbours to bear.

      Seriously though I’m not trying to pretend that I am undertaking any of this with scientific rigour.

      1. Long sleeves then? See, I read this blog with pleasure and value what you write. I’m just afraid that next time I’ll see “Fenix 3 registered 0 distance in this test, but it could be because of it was sitting in a drawer while I was running” 😉

      2. well…at least I hope I would be honest enough to say (in a footnote) that I left it in the drawer 🙂 Hey!!! you’re my reader…awesome. I always wondered who it was.

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