garmin veteran user in depth comparison of fr645

Preface

It has been two years since Garmin released its last mid-range running watch, the FR630. According to Garmin's update routine, it's time to release a new generation product.So, this summer, the upgraded mid-range running watch Forerunner 645 (hereinafter referred to as 645) has arrived.

The 645 comes in two versions: the standard 645 and the music version 645M.

Compared to the standard 645, the music version 645M adds an offline music function, upgrades to 3.5GB of memory, and has two more hours of battery life in GPS mode, reaching 14 hours. However, if you enable the music GPS mode, the battery life will be shorter than the standard version.

The official price for the standard version is 2780.

The official price for the music version is 3280.

The new 645 has significant upgrades compared to the old 630. The main changes are the support for music and wireless payments. The appearance features a nice metal bezel, significantly enhancing its look and feel. It also includes Garmin's wrist-based optical heart rate monitor and quick-release straps. The standout features are mobile payments and music functionality, making it a better choice for those who can't run without music. The GARMIN PAY wireless payment feature is very convenient for buying a bottle of water after exercise with just a swipe of the watch. This review is for the standard 645.

Garmin has a characteristic of applying some new technologies to new products other than the flagship models first to see if the user experience is reliable before deciding whether to include them in the new flagship models. Of course, the flagship models will also include a lot of advanced technology; otherwise, how would they sell?

The 645 incorporates many of Garmin's new technologies, such as a brighter screen, faster charging, quicker screen response, more comfortable button feel, and the addition of music and mobile payments. I think the next generation flagship Fenix 6 series will continue these new technologies and add other advanced features. The 645 is more like a testbed for new technologies. Why do I say this? Because I did an asymmetric comparison review between the 645 and its big brother, the Garmin Fenix 5, and concluded that the 645 is not inferior to the Fenix 5 and is even better in some aspects! Let me explain in detail.

Unboxing Overview

Let's start with an unboxing video.

This is the fifth Garmin watch I've used, and my impression is that Garmin's product packaging always has that familiar feel—simple, elegant, and textured.

The cool black and gray outer packaging showcases the 645 with a full-face effect picture. Both sides of the box introduce the features of the 645, and the back lists the production location (Taiwan, China) and the product directory.

Compared to the Fenix 5's packaging, the 645's packaging is much more low-key, clearly indicating that the Fenix 5 is of a higher grade.

The accessory list includes a manual, USB data cable, and the 645 watch.

The dimensions of the 645 are 42.5x42.5x13.5mm.

The dimensions of the Fenix 5 are 47x47x15.5mm.

In terms of appearance, the 645 is delicate and elegant, while the Fenix 5 is robust and domineering. The 645 weighs only 42 grams, while the Fenix 5 weighs 84 grams! The 645 offers a superior wearing experience, feeling almost weightless even during long periods of wear, whereas the Fenix 5 is noticeably less comfortable.

Both the 645 and the Fenix 5 feature a 1.2-inch semi-reflective screen with a resolution of 240x240. However, despite the Fenix 5 having a diameter of 47mm and the 645 only 42mm, they have the same effective display area because the 645 uses a narrow bezel design, offering a larger display area. Surprisingly, the 645 is noticeably brighter than the Fenix 5, even though both have the same 240x240 resolution. Additionally, the 645's screen response speed is faster than the Fenix 5's.

The 645's front bezel is made of stainless steel, instantly enhancing its grade. The polishing and edge grinding of the bezel are excellent, almost blindingly shiny! However, the stainless steel bezel will inevitably get scratched over time, especially the white bezel, where scratches are more noticeable. Why not use the PVD coating from the Vivoactive 3? Perhaps it's a cost issue. In comparison, the Fenix 5's bezel feels more robust and has better wear resistance. After wearing it for over half a year, there are no scratches on the bezel, and the back also uses metal with a sunburst texture, which is excellent. Of course, the two are not comparable because they have different positioning.

The 645 does not use the touch screen from the Vivoactive 3. Personally, I think the touch screen on the Vivoactive 3 is not mature enough. The 645 returns to the classic left-three-right-two button layout, which proves to be very reasonable in design and more convenient to operate than a touch screen.

The button feel of the 645 is better than any Garmin watch I've used. The tactile feedback is excellent, with moderate resistance after pressing. The vibration alerts of the 645 are also much gentler than the Fenix 5's. The gentle vibrations provide a better experience, unlike the Fenix 5's strong vibrations, which can be annoying when there are many notifications. The 645 doesn't have this issue. Considering the Fenix 5 is positioned as an outdoor watch, the stiff button settings are understandable, mainly to prevent accidental touches in outdoor environments.

The 645's body and back are made of matte-textured polycarbonate plastic, which is lightweight. However, it doesn't feel as premium as metal.

Both the 645 and the Fenix 5 use Garmin's Elevate wrist-based optical heart rate monitor, which has been applied to many Garmin products like the 235, 735, 935, and Fenix 5. This optical heart rate monitor has been tested over time and is a very mature product with reliable accuracy.

Both the 645 and the Fenix 5 use medical-grade silicone straps, which are soft and comfortable for long-term wear. The 645's strap has a water ripple pattern for better slip resistance and uses a quick-release design. Compared to the Fenix 5's quick-release strap, the 645 uses a more common spring bar, while the Fenix 5 uses the QuickFit quick-release strap. Both support interchangeable straps, with various colors and materials available on the official website. The 645's strap width is 20mm, and the Fenix 5's is 22mm. Both straps are comfortable to wear, but the Fenix 5's quick-release mechanism is more convenient.

The USB charging cable of the 645 is slightly different from the Fenix 5. The 645 uses a clip-on charger, while the Fenix 5 uses a push-in charger. From my personal experience, the clip-on charger of the 645 is better. The push-in charger of the Fenix 5, although aesthetically pleasing, is easily affected by sweat and can pop out easily, especially when you need to charge it quickly after exercise. The charging port can become loose due to sweat, which is quite frustrating and also tends to attract dust, making it difficult to clean. I hope Garmin can improve this. Garmin, have you considered a magnetic charger?

The 645 charges significantly faster than the Fenix 5. In my tests, the 645 took only one hour to charge from 50% to 100%, while the Fenix 5 took about three hours. This might be due to the different battery sizes. Both support charging during exercise.

Experience

Garmin's watch operating system is the best in its class, bar none! I once reviewed a sports watch from a Japanese brand, and its operating system was simply anti-human design!

Garmin's operating system is straightforward, easy to understand, and practical.

The 645 supports dual-mode GPS positioning (GPS+GLONASS), while the Fenix 5 supports triple-mode positioning and also has outdoor ABC technology.

I have conducted several accuracy tests with the 645 and the Fenix 5, wearing the 645 on one wrist and the Fenix 5 on the other, both in sports mode, for running and cycling tests. In terms of GPS accuracy, the Fenix 5 is slightly better than the 645. The following image shows the track comparison, where the 645 has some drift, while the Fenix 5, with its triple satellite mode, has higher accuracy.

Garmin watches support Codoon Sports. Just take your watch out for a run, and after you're done, sync it to Codoon. This is very convenient, allowing you to leave your phone behind and enjoy your run.

Sports Testing

I won't go into too much detail about the system interface. In short, it's simple, easy to use, and understandable. As long as you understand Chinese, it won't be difficult. Here, I'll focus on the 645's 'hidden' features.

For example, how to design a training plan, how to analyze running dynamics, how to change the watch face, etc.

Long press the UP button to bring up the system menu, where you can set a personalized watch face, alarm clock, view history, system settings, and more.

How to set a training plan: In the sports menu, select the training project you want to set, such as running, then long press the UP button to enter the running settings interface. You can set your desired training plan, such as interval training, personalized data interface, navigation, metronome, virtual partner, and more. The virtual partner feature is particularly impressive. You can set a pace for the virtual partner, and it will accompany you at that pace. If you are ahead or behind, it will show. This is great for pace runs during the preparation period, making the 645 your training partner. The advanced running dynamics of the 645 require the use of the Running Dynamics Pod, which is available from the official store.

The Garmin 645 supports up to twenty sports modes, such as running, cycling, pool swimming, hiking, skiing, parachuting, aerobic exercise, and strength training. However, it does not support triathlon or open water swimming modes because the 645 is positioned as a running watch. While it has powerful running features, it does not support multi-sport modes.

Daily Use

In daily life, the 645 supports 24/7 heart rate monitoring, steps, calories, sleep monitoring, sedentary reminders, music control, smart notifications, and even a flashlight function.

The most attractive feature of the 645 for me is the GARMIN PAY wireless payment function. You can buy water without a phone while running, which is fantastic! Since GARMIN PAY has just launched in China, it currently supports only a few banks, as shown in the image below. More banks will be supported soon. The Fenix 5 series does not support mobile payments.

Summary of Pros and Cons

Pros: High appearance, comfortable wearing experience, mobile payment, offline music (limited to 645M), powerful advanced running dynamics analysis, interchangeable straps, brighter screen, faster charging, etc.

Cons: The metal bezel is not wear-resistant, battery life is slightly short, and it does not support triathlon mode. No other obvious shortcomings have been found for now.

Recommendation

The new 645 has a very clear positioning: it is aimed at advanced runners who focus on marathon training and stylish women who love sports. Its appearance is more suitable for women, and it is also very good for daily wear—simple, elegant, and textured. The addition of offline music and wireless payments makes the 645 more fun. Choosing Garmin products is never wrong. I highly recommend it.