GPS test | Polar Grit X vs Suunto 9 with BeiDou

2 tests after the last firmware update by Suunto

Movilan - Accesorios telefonía móvil

Esta página está disponible en español



The Polar Grit X full review is already published.

This article is only a small test, so if you want to know all the details of the watch, how it works and the my full detailed opinion, click on the following link:

Polar Grit X | Full in-depth review and opinion

One of the things I had to do since the beginning of the pandemic was to test out the new Suunto update. And it was pending since March (we're up to May... wow!), so now that we've been able to train outdoors, it was a matter of checking this out from the to-do list.

The test I wanted to do was specifically about GPS performance. I have not yet had the opportunity to test the improvements in the barometric altimeter, because I can't drive to the mountains yet (we must train in our town at the moment, it's not possible to cross to a different place) and because I would need a few hours run with sudden changes in barometric pressure, which is not something that happens frequently in Marbella.

And since I already talked to you enough about the integration with Training Peaks on the firmware's release day, I only had to comment on the performance of the GPS+Beidou option, which according to internal sources from Suunto it offered a great performance improvement.

Also, as I am in the middle of the Polar Grit X review, I have a great chance of testing both things at the same time.

Since the confinement was lifted I have been able to perform two run workouts in which I have combined the Grit X together with the Suunto 9, of course accompanied by more devices to verify the data. In addition, they are not excessively easy tests because I am running at a somewhat slower pace than usual, because despite having been able to train on the treadmill, it's not the same as running outside.

And why running slower is worse for the GPS tracks? Because by recording location points every second, they are closer to each other and makes the tracks appear uglier, or small errors get more noticed. It is for the same reason that in cycling the tracks are usually so beautiful, because the distance between one point and the other is much greater than running or walking.

Test #1

>> Check it out
GLONASS and Galileo. What is it and when to use it

So I start with this short workout of only 4 kilometers, which was also the second session of the day and the recommendation from my coach was to make it EASY. As I am very disciplined, I did it at a slow pace of 6:28 min/km on average. As I indicated earlier, it is far from ideal conditions for a GPS watch.

For this test, in addition to the Suunto 9 Baro (again, in its latest firmware version and with GPS+Beidou option enabled) and the Polar Grit X (configured in GPS+GLONASS); I also carried the Polar Vantage M (GPS+Galileo) and Garmin FR945 (GPS+GLONASS).

By the way, I just restored the FR945 because lately it was giving me horrific GPS performance.

Comparativa GPS Suunto 9 y Polar Grit XThe first impression is really good on all four watches. At least, from a bird's eye view, none of them have deviated from the route and the lines drawn are quite straight. But let's zoom in to see the details better.

This is the beginning of the training, but already advanced a few meters so the signal quality should already be reasonably good. It's not an easy zone because I run under some metal structures that give shade, and they can make a little of a Faraday cage effect.

Comparativa GPS Suunto 9 y Polar Grit X

On the Grit X I have already seen a behavior that has been very common in the Vantage M and Vantage V. A slight positioning error, but that persists over time. It is not too important because in the end all you are doing is moving the track 2-3 meters out of the actual location, but the measurement of pace and distance is correct because by persisting in the error it draws a completely straight line parallel to the real track.

I mean, it's not very important, but none of the other three watches have it. Neither does Vantage M, although it is true that its satellite configuration is not the same (GLONASS on Grit X and Galileo on Vantage M).

Later we can see that the Grit X is still committed to moving slightly to the right of the correct route, when none of the other three have. And by the way, I haven't mentioned it yet, but Suunto 9 has been perfect so far.

Comparativa GPS Suunto 9 y Polar Grit X

However in the following image is the Suunto 9 the one that has shifted a bit compared to the other tracks. The area I have pointed out with the arrow is a moment when I get off the road to avoid people walking along the sidewalk (social distancing and such), something that every watch has recorded perfectly, except the Suunto 9.

Comparativa GPS Suunto 9 y Polar Grit X

Same thing happens here, I go down to the road to make room and every watch obeys... except the Grit X that keeps making a straight line.

Comparativa GPS Suunto 9 y Polar Grit X

In the second arrow you can see that the Grit X repeats the mistake for which the Polar have been known... although it is true that in the Vantage M it is not appreciated at any time. By the way, I haven't mentioned it yet, but it seems that restoring the FR945 firmware solved the issues I was having with it. As I said, the tracks that were coming out from it were horrendous.

Buscador de chollos

Let's go on... complicated place. Crossing the highway by a bridge over it, to which I reach at the a slow pace and I still don't want to go over zone 2. The result is that I go uphill even slower, making a 180 degree turn.

Comparativa GPS Suunto 9 y Polar Grit X

The only watch that has correctly recorded the climb (which is on the side next to the parking lot) is the Garmin. The other three have diverted. Again on the descent is the Garmin that has been the most accurate, with the Vantage M and the Suunto 9 following closely. The Grit X has again made the descent knot with a displacement of a few meters.

But the Garmin has not always done the correct route, shortly after the descent of the bridge the Grit X and FR945 move towards the sidewalk on the left while the Vantage M and Suunto 9 making the correct route.

As you can see the Grit X is already dragging the error (and I don't want to be a broken record... but it's what I've been seeing in the Vantages for years), but the 945 is inexplicably shifted halfway and that's less common.

Comparativa GPS Suunto 9 y Polar Grit X

It doesn't always have to be mistakes. There are also times when the four fully agree, which is what really has to happen.

Comparativa GPS Suunto 9 y Polar Grit X

Test #2

Let's go to the second test. On this occasion I replace the Vantage M with the COROS APEX Pro, with GPS + GLONASS. A slightly faster workout than the previous one but also not lightning fast (5:50 min/km on average).

One of my usual routes, so I'm going to focus on the points I know are always more conflicting. To add details, this day was cloudy, making it more difficult to receive satellite signal (in test #1 it was completely sunny).

In the first image before we zoom in we can already see that there is something strange in the Suunto track... but we will get to that point later on.

Comparativa GPS Suunto 9 y Polar Grit X

At the beginning of the route one thing that catches the eye is that the COROS happens to have a similar error to what suffered the Grit X in the first run. It goes into an error of 3-4 meters and keeps it. As I say it is not excessively important, because the distance and pace that you get will be the right ones, it's just that the track is off and you can see it on the map.

Comparativa GPS Suunto 9 y Polar Grit X

Let's go to the first of the hotspots, a turn of about 100 degrees. The Polar Grit X (still in GPS+GLONASS) reaches that point with the same error we've been seeing so far, but it takes the corner correctly, as does the COROS and Garmin. But the Suunto cuts the corner by a few meters.

Comparativa GPS Suunto 9 y Polar Grit X

That can be more problematic if it happens constantly, because in a long workout or marathon race, those two meters from here plus those two meters from there can end up accumulating a good hundred meters.

Next hotspot. Historically, the pass over the bridge and the turn after crossing it often creates problems. In this case, apart from more or less meters of displacement by almost evey watch (the COROS has the correct path), the turn is reasonably good, within the error of being a few meters off the actual route, especially noticeable in the case of Garmin and Grit X.

Comparativa GPS Suunto 9 y Polar Grit X

This turn is usually very problematic, as two changes of direction are made in very little ground space. The COROS APEX Pro nails it, while the other three behave reasonably well, always considering that at the turning point they arrive slightly displaced.

Comparativa GPS Suunto 9 y Polar Grit X

Later the Suunto begins to get lost. You can see that while COROS, Garmin and Polar make the correct turn and continue along the promenade route, the Suunto makes a “break” before the turn point and then takes some time to recover. That is, it has reached that turning point with not too many satellites from which it can obtain data.

Comparativa GPS Suunto 9 y Polar Grit X

But at the exit of Puerto Banus is where it loses it completely, which is what you saw in the first picture.

Comparativa GPS Suunto 9 y Polar Grit X

This time the Suunto does not have much justification, because none of the other three watches present any problems.

The next point I like to observe is when crossing the road through a passage below the highway. At this point the watches lose the signal, because I spend several seconds under the road, and what interests me is to observe what is the behavior both inside the tunnel and the speed to recover the signal when leaving the tunnel.

Comparativa GPS Suunto 9 y Polar Grit X

Suunto 9 takes the easy path and simply joins the point where it has lost the signal with which it has recovered (and took a little longer than the others). Remember what I just said in reference to continuously trimming corners? Well, we keep adding meters...

Meanwhile the Polar Grit X and the COROS APEX Pro make the stretch under the highway perfectly, identifying that we have run in that direction even when they were not receiving GPS signal. They make some strangers movements out of the tunnel, but it's totally normal considering the situation.

Garmin for its part is also lost quite similar to Suunto, although performing the recovery in the opposite direction.

Little more to stand out from this workout, beyond noting that sometimes there is separation of two tracks. The reason? I have the Grit X and FR945 on my left arm and hand, and the COROS and Suunto on my right arm and hand, so each tends to deviate slightly to that side.

Comparativa GPS Suunto 9 y Polar Grit X

So just to be clear on which of the four was on the right path in this last image, it is the Grit X that shows the correct track in that section.

Bottom line

After these two tests I have been able to come to some conclusions which I will detail below:

  • Suunto 9: With the use of BeiDou satellites the performance is good, but not perfect. Especially in the second test it is where it has had the most notable failures. But remember, no matter how many updates the manufacturers make, a GPS watch is not a precision tool and will always be exposed to more or less important errors.
  • Polar Grit X: The initial result is not bad, but it strikes me a lot that with the two Polar at once, the one in GPS+GLONASS (the Grit X) has the offset and the one in GPS+Galileo (the Vantage M) does not. So the following tests that I do for the full review on the Polar Grit X will be performed with GPS + Galileo to see if the tracks improves. It is curious that the COROS has had similar behavior being also in GPS+GLONASS... It is possible that there is some specific situation with the Russian satellite system at the moment.
  • Garmin FR945: If you have problems with tracks or GPS reception of any watch... rule number 1: restore it back to stock. In the case of Garmin the improvement has been HUGE.

The full review on the Grit X will be published in about a couple weeks, so keep in mind if it's a model you're interested in to come back and check it out.

I hope you stay well, totally healthy and starting to recover your usual workouts. Thanks for reading!

Do you want to be always up to date?

Join the community







Related Articles


  1. Yo tengo un Polar Vantage M, y en mi zona (centro de Asturias) me funciona mucho mejor en GPS + Galileo, si esta en GPS + Glonass tiende a equivocarse más en giros cerrados, zona de edificios altos, etc. Obviamente no es perfecto en ningún modo, pero en general mejora bastante, y en trail tambien funciona mejor con Galileo. Quiza al Grit X le pase algo similar.

    Leyendo tu articulo entiendo perfectamente lo que dices de los Vantage, en una de mis rutas más habituales voy siguiendo una carretera con curvas amplisimas durante 2 kilometros, justo al comienzo del entreno, y es habitual que marque el track a 1 o 2 metros de la acera, pero lo hace constante durante esos 2 kilometros, por tanto el ritmo y distancia se marca correctamente,y justo cuando hago un giro de 90 grados para cruzar una presa, que me salgo de esa carretera, y es el primer cambio de “rumbo” brusco, pasa a marcar el track perfecto a partir de entonces.

  2. Como siempre y una vez más, gracias por tus análisis.
    Siempre he sido de Suunto, Ambit2s, Ambit3 Sport, 3 Peak, Spartan Ultra… hace 2 meses vendí el Spartan y me he quedado con el Peak porque es el que mejor va. Todo mi equipo tiene Garmin y hacemos retos y desafíos internos como aliciente, y me estoy planteando coger un Fenix 5x Plus o un 945, pero Suunto me sigue llamando mucho la atención, el 9 me gusta mucho, pero me echa mucho para atrás la experiencia con Spartan y todo el ecosistema de la web, las app´s que ahora no se pueden instalar en el reloj o la App Suunto. Llevo un tiempo y sigo sin saber que hacer…

  3. Gracias por la comparativa! Muy buen test!
    Cierta inestabilidad, perdidas de señal, recorte de curvas, lineas rectas y bamboleo son unos problemas bastante persistente en Suunto. Llevan años sin encontrar la solución. Aunque no afecta mucho a la distancia medida es bastante molesto para los que nos gusta la precisión. Precisamente era el motivo (entre otros) de cambiarme de Suunto 9 a Coros. El Finlandés nunca ha estado a la altura de cualquier Ambit Peak de su propia casa.
    Al respecto: ..correr más despacio el GPS lo pasa peor? O incluso caminar. Es un mito que siempre ha transmitido la marca finlandesa. Si una mentir se repite 1000 veces se convierte en un mito o una verdad. O ambos. No puedo estar de acuerdo porque estoy en posesión de un reloj con chipset Sony y esto no afecta la calidad del track de lo mas mínimo o de un modo prácticamente inapercebible.
    Por otra parte me gustaría añadir que también he observado algunos errores típicos de los que mencionas en tu análisis de GLONASS. BEIDOU lo hace mejor. Creo que por fin tenemos una constelación que funciona muy, pero muy bien. La combinación GPS+BDS es muy precisa y estable. Todavía desconozco su impacto directo sobre la duración de batería.
    A salute.

  4. Gran análisis. Ya estoy impaciente por ver la prueba del grit x con galileo a ver si las mejoras son notables. Y también de verlo en montaña que está enfocado para ese fin y saber que tal responde esas novedades que aporta respecto a los otros modelos. Un saludo y gracias por estas pruebas.

    1. Gracias Sergio.

      Sigo trabajando con él, en las próximas semanas estará la prueba publicada.

      En cuanto a las montañas no va a ser fácil dadas las dificultades que tenemos ahora mismo. Pero vamos, para probar bien probado Hill Splitter y FuelWise tampoco necesito tanto campo…

  5. Gran análisis de nuevo Eduardo
    Al igual que Sergio, también espero con gran inquietud el análisis completo del Grit X-
    Llevo cuatro dias con el y poco a poco voy cogiendole el aire.
    A hug.

  6. Hola, en primer gracias por tu excelente trabajo, no te quepa la menor duda de que cada vez que compro algo tiro de enlace del blog, que menos.
    Mi pregunta, aprovechando la revisita al Polar Grit… es posible configurar la pantalla principal de los polar para mostrar la hora de la salida y puesta de sol? Se que es una pijada, pero en mi garmin 920xt es una cosa que usaba muchísimo, sobre todo para de un vistazo saber si me daba tiempo a salir o me iba al rodillo… un pijada pero puede ser lo que me haga decidirme entre Garmin, Polar o Suunto, tengo ganas de cambiar a Polar por haberlo ansiado desde crío cuando eran los mas punteros, he tenido mucho tiempo garmin, tanto edge como forerunner, pero me apetece probar algo nuevo y mas “elegante” del tipo Suunto 9 o Polar vantage v titan // Grit, así mi diatriba depende de un factor tan irrelevante para otros como ese.

    Thank you very much!

      1. Muchas gracias por la rápida respuesta… voy a leerme la review entera pero sin eso… es que es una pijada si, pero le doy mucha importancia xD

        Puede que la cosa esté entre un grande y elegante suunto o un garmin… ya se verá.

        A salute!!!

Leave a Reply

Your email address will not be published. Los campos obligatorios están marcados con *

Through this form the data are treated with the only purpose of being able to manage your comments.

These data will be recorded on the server, unless you check the box to subscribe to the newsletter that will be stored in the list of Mailchimp (which also complies with all laws). At any time you can request both the cancellation of any of the emails and the removal of all your data.

For more information you can check the privacy policies for more information on where, how and why I store your data.

And I'm sorry about the bilge, but I'm obliged to put it in.

Back to top button