Since I use the watches for running, this post is primarily oriented toward running. However, both watches are capable of much more. They are truly multi-sport watches; capable of handling a triathlon and other activities. Unfortunately, I haven’t had the opportunity to test many of these features (since I don’t swim or ride often) so my comments are primarily geared toward trail and ultra-running.
I’ve been running with the Garmin fenix 3 since this past March 2015. Overall, it has served me fairly well. I used it during The North Face Endurance Challenge GORE-TEX 50 Mile race in April 2015 and it performed flawlessly.
However, it has also frustrated me on a few occasions. For a few weeks in October, it was taking a long time to acquire satellites. It turned out there was a GPS firmware update that wasn’t being applied.
Then during the JFK 50 Mile race in November, the fenix 3 lost satellite reception for about five miles on the Appalachian Trail. It finally re-acquired a GPS signal once I left the trail and started on the C&O Canal towpath part of the course.
So while the Garmin fenix 3 has worked well overall, those few nagging issues always made me want to try the Suunto Ambit3 Peak and see how it performed. So when I saw the Ambit3 Peak Sapphire on sale, my curiosity finally got the best of me and I decided to give it a try.
Now that I have used the Ambit3 Peak for about 6 weeks, below are my thoughts on how it and the fenix 3 compare.
GPS Acquisition / Accuracy
GPS acquisition and accuracy are the main reasons why I was curious about the Ambit3 Peak. If you browse the Garmin fenix 3 forums, you will see many threads about the accuracy issues of the fenix 3. Inevitably, someone in these threads will bring up the Ambit3 Peak and talk about how it “just works”.
This made me curious. As I mentioned above, I had experienced some issues with the fenix 3, although not as many as some in these forums. In general, I would say that mine has performed well overall. There have been a few issues, but no device is perfect.
However, those comments peaked my curiosity and it was going to be hard to let it go. Does the Ambit3 Peak have better GPS accuracy? How do these two watches compare?
First, let me say that my testing was not scientific. Nor do I have as many runs in the Ambit3 Peak as I do in the fenix 3.
Below are few screen captures of a portion of the Rehoboth Beach Marathon, in which I wore both the fenix 3 and Ambit3 Peak.
The fenix 3 is in orange and the Ambit3 Peak is blue.
As you can see, the Ambit3 Peak tracks (blue) were consistently inside the fenix 3 tracks (orange). The Ambit3 Peak tracks were generally on the road or trail whereas the fenix 3 tracks were often off the road or trail completely. This was consistent for the full marathon.
In this run, it is easy to see that the Ambit3 Peak performed better.
However, here is another run on a trail in my neighborhood. Again, the fenix 3 is in orange and the Ambit3 Peak is blue.
In this case, the fenix 3 tracks were inside the Ambit3 tracks. In this instance, I would say that the fenix 3 performed better.
I could go on with examples. In some cases, the Ambit3 Peak seemed to have the better tracks. In other cases, the fenix 3 seemed better.
However, if I had to make a call between the two, I would say the Ambit3 Peak was probably more consistent overall.
The same is true regarding acquisition time. The Ambit3 Peak always locked onto a GPS signal within a few seconds. Rarely have I had it go longer than 5 seconds. In most cases, the fenix 3 is also similarly fast. However, in my experience, the fenix 3 has been less consistent. I’ve experienced the fenix 3 taking 1 minute, 3 minutes, and upwards of 20 minutes to lock onto the GPS signal. When I’ve run with the two watches together, the Ambit 3 Peak was consistently a few seconds faster.
One additional item of note. Garmin supports GLONASS, which is the Russian satellite system. This theoretically might give in better accuracy in some situations. However, I haven’t noticed much of a difference in my area.
So overall, I would say that the Ambit3 Peak has the slight edge in this category.
Winner: Slight edge for Ambit3 Peak. However, from my limited testing, it was not as drastic a difference as you might be led to believe by reading the forums.
Another factor that I look for in comparing two watches is the battery life. When I run an ultramarathon, I want to be sure my watch can last the entire run.
First, what do the specifications claim?
Garmin fenix 3 – The fenix 3 has two GPS modes to adjust battery life:
- In normal GPS mode (one GPS update per second) – 20 hours.
- In UltraTrac mode (approximately 15 seconds of GPS on-time per 60 seconds) – 50 hours.
Suunto Ambit 3 Peak – The Ambit3 Peak has three GPS modes to adjust battery life:
- In the best GPS mode (one GPS update per second) – 20 hours.
- In one GPS update per 5 second mode – 30 hours.
- In one GPS update per 60 second mode – 200 hours.
To be clear, there are other settings that will impact battery such as Bluetooth, notifications, connected sensors (i.e., heart rate monitor), etc.
To test the battery, I tried to maximize the battery life by disabling Bluetooth, Wi-Fi (fenix 3 only), sensor support, and anything else I could think of that might reduce battery life.
Then, I simply charged the watches fully and let them lock onto GPS satellites. I then started a running activity and just let the watches run for as long as they could. I set the watches in my car, near the back windshield so they could see the GPS satellites all the time. It wasn’t ideal, but it was the best place I had that had a clear view of the sky and would be secure.
The results are as follows. In both cases, I synced the respective activities to Garmin Connect and Suunto Movescount to view the resulting times.
The Ambit3 Peak recorded the activity for just over 21:00:28 (21 hours and 28 seconds) before it automatically stopped the activity and went into power save mode. It had about 3% battery left when I retrieved it.
The fenix 3, on the other hand, lasted for only 16:45:19 (16 hours, 45 minutes, and 19 seconds). The fenix 3 also appeared to shut down completely with 0 percent battery left.
In summary, the Ambit3 Peak battery lasted for about 4 hours and 15 minutes longer than the fenix 3.
There is one caveat, however. I have used the fenix 3 for about 8 months while the Ambit3 Peak was fairly new. So that could account for some of the battery difference. However, I find that over 4 hours is still a lot of difference.
In addition, as mentioned above, the Ambit3 Peak has more battery configuration options and one option that allows the watch to last approximately 200 hours in activity recording mode.
So, overall, I’m giving this win to the Ambit3 Peak.
Winner: Ambit3 Peak
I’ll be honest, this once surprised me a bit.
I fully expected the Garmin fenix 3 to be more comfortable due to how the band is designed. In the fenix 3, the GPS antenna is in the bezel, so the band is fully flexible where it attaches to the watch face. See the picture below.
I would expect that this allows the watch to fit a wide variety of wrist sizes. I used to run in the Garmin Forerunner 610, which didn’t have the flexible band and I didn’t find that as comfortable.
The Ambit3 Peak, on the other hand, has the GPS antenna where the watch face attaches to the band. In addition, where the band attaches to the watch face is not as flexible. See the picture below. The GPS antenna is on the right side.
Due to these differences and my past experience with the similarly designed Forerunner 610, I expected the fenix 3 to be more comfortable.
However, surprisingly, I found the Ambit3 Peak to be the more comfortable of the two watches. Despite the lack of flexibility where the band connects to the watch, I felt that the Ambit 3 Peak fit me perfectly. In addition, the underside of the Ambit 3 has smooth and rounded edges. The fenix 3, on the other hand, has flatter and more rough edges. In addition, the Sapphire band is very soft and smooth. So overall, the Ambit 3 Peak had less movement when running and just disappeared on my wrist.
Don’t get me wrong, the fenix 3 is plenty comfortable, but for me, the Ambit3 Peak was just more comfortable overall.
Again, one caveat. Due to the lack of flexibility in where the band meets the watch, the Ambit3 may not fit all wrist sizes well. So if you have a extra large or extra small wrists, the fenix 3 may be a better choice due to the extra flexibility.
Winner: Ambit3, but this is a personal preference.
I won’t spend much time on this one since I think it is subjective. Both watches look very good. However, I think the fenix 3 looks better overall. With the GPS antenna in the bezel, the watch has a more sleek look. If I had to choose a watch to wear every day based on looks alone, I would choose the fenix 3.
Winner: fenix 3
Display / Screen
This one isn’t subjective. There is really no contest. The fenix 3 has the better display / screen. It has higher resolution which makes it easier to read. In addition, the blacks are blacker and it has color. Overall, the display on the fenix 3 is outstanding. The Ambit3 Peak display is adequate, but looks like an old pixelated calculator. There were often times in the high sun, that I found the Ambit3 display difficult to read.
Winner: fenix 3 by a wide margin.
Both watches have a multitude of features such as track recording, barometric altimeter, compass, navigation, weather, track back, and other various sports metrics such as cadence, power, etc.
In addition, both watches are multi-sport watches and can support running, swimming, biking, hiking, and a number of other activities. Both watches have a multi-sport mode to support triathlons, where you can switch from one sport to another within the same GPS recording activity.
Both watches support pairing with external sensors. The Ambit3 only supports Bluetooth sensors, whereas the fenix 3 supports ANT sensors. At least for the moment, the fenix 3 support of ANT sensors probably provides the most options in external sensor support.
However, there are a few key differences in features between the two watches.
First and foremost, the fenix 3 supports vibration alerts. To me, this is one of the biggest features lacking on the Ambit3. The Ambit3 has tone alerts, but when running with headphones, as I sometimes do on long runs, it is not always easy to hear the tone. I try not to look at my watch when I run as doing so makes the run seem that much longer. However, without vibration alerts on the Ambit3, I find that I have to look at the watch more often to make sure I don’t miss my turn around point.
In addition, the fenix 3 allows you to change all settings on the watch, outside setting up the WiFi network connection. The Ambit 3 requires the use of the website or phone to change certain settings and to set up the activity sport screens. See my review of the Ambit3 Peak for more discussion of this. This can be a big deal if you are without internet or data connection to the Movescount website. If the website goes down or if you are without data connection, you are simply unable to change any of these settings.
Also, the fenix 3 supports four data fields per screen and the Ambit3 Peak only supports 3 data fields per screen.
Furthermore, besides connecting via USB to a computer, the fenix 3 supports both WiFi and Bluetooth (via phone) synchronization. The Ambit3 only supports USB and Bluetooth.
Lastly, the fenix 3 supports a GLONASS satellite mode, but I haven’t noticed much difference with this enabled. However, I imagine future Suunto Ambit watches will support GLONASS since it is supported on the new Suunto Traverse.
So overall, I think the Garmin fenix 3 has more features that I care about than the Suunto Ambit3 Peak.
Winner: fenix 3
How well it works
The last comparison is a catch-all category for how well the watch works.
While many people complain about the GPS accuracy on the fenix 3, I find that it is adequate. I do get frustrated at the long GPS acquisition times on random occasion. However, it does eventually acquire the GPS signal. I find that if I sync the Garmin via USB more often instead of over WiFi or Bluetooth, then the acquisition time improves. This may have something to do with caching the GPS satellite positions. I believe the satellite cache is supposed to be updated via WiFI as well, but perhaps this is not the case.
However, I have observed that running cadence is one feature on the Ambit3 Peak which simply does not work well at all.
Both watches have an internal accelerometer to measure running cadence based on wrist movements. However, refer to the screen captures below of the running cadence measurements from the Rehoboth Beach Marathon. Notice how the Ambit3 Peak is much more flakey and has frequent drop-outs. I’ve noticed this in almost all of my runs with the Ambit3. The running cadence measurement just isn’t reliable and often drops-outs when you increase the pace.
I contacted Suunto and they said that the accelerometer on the watch is defective and I should send it in for repair. So you might think that my watch is just a rare case of a defective hardware component.
However, when I look at other peoples runs in Strava that use the Ambit3, I notice the same thing. There seem to be cadence issues on a majority of the activities I see. So it appears that my watch is not just an isolated case. Perhaps others don’t mind the flakiness of this feature, but it annoys me nonetheless. Due to the apparent prevalence of this issue, I don’t have confidence that if I send the watch back to Suunto or if I purchased another Ambit3 Peak, the issue won’t still be there.
Others may have a different experience or may have other issues with the fenix 3. But in my experience, the fenix 3 doesn’t have a feature that is as flakey as this.
Maybe I am being a little unfair to the Ambit3. If you don’t care about running cadence, then the Ambit3 Peak functions perfectly. In addition, running cadence isn’t a key feature of the watch. It has great GPS acquisition and accuracy, perhaps slightly better than the fenix 3. However, with the frequency I have seen the running cadence issue in the activities of others, it makes me think that Suunto has an outstanding hardware or software issue they need to address. And with that, I have to give this category to the fenix 3.
Winner: fenix 3
While there are many areas in which I could compare the two watches, I tried to capture the major areas that I would consider when deciding between the two watches. Others may have different opinions or other areas of importance. If so, let me know in the comments below and I’ll respond with my thoughts.
Overall, if GPS quality and battery life are your most important factors (and they are arguably the two most important factors for an ultramarathoner), the Ambit3 Peak is the winner.
However, the fenix 3 excels at other features such as vibration alerts, display quality, and quality of other non-GPS related features such as cadence and external sensor support.
So in the end, both are excellent watches. When making a decision between the two, you just need to decide which features are more important to you. For now, I’ll be returning the Ambit3 Peak due to the internal accelerometer and cadence issue. However, I may still give it another try if I see a good deal in the future.
As always, comments are appreciated. Let me know of any thoughts or questions below. I hope you found this post useful. Thanks for reading.