Les modes GPS expliqués : lequel choisir ?

Day 55: GPS Accuracy Modes Explained

Your Garmin has multiple GPS modes, but what's the actual difference — and which one should you pick? Here's the breakdown.

The modes

Most Garmin watches give you at least three options: Off, GPS only, and All Systems. Some models also offer Multi-Band and UltraTrac.

What each mode actually does

• GPS only — uses American satellites exclusively. Fast lock, decent accuracy, solid battery life.
• All Systems — adds European (Galileo), Russian (GLONASS), and Japanese (QZSS) satellite networks on top of GPS. More signals = faster lock + better accuracy, especially in tricky environments. Slightly higher battery drain.
• Multi-Band — uses multiple radio frequencies per satellite rather than just one. This dramatically reduces signal errors caused by buildings, trees, and terrain. The most accurate mode available, but the biggest battery hit.
• UltraTrac — trades accuracy for endurance. Your watch takes GPS readings less frequently to stretch battery as far as possible. Useful for multi-day events. Not ideal if you care about track detail.

When to use each one

• Open field or trail run with no obstacles → GPS only is totally fine.
• City running with tall buildings, or dense forest → All Systems locks on faster and keeps your track much cleaner.
• Racing or when precision really counts → Multi-Band gives you the sharpest data.
• Ultra-distance event where battery is everything → UltraTrac stretches it as far as possible, just accept the trade-off in detail.

The default setting on most watches is GPS only. It's a reasonable middle ground — but if you're regularly running in cities or forests, switching to All Systems is a quick win for almost no cost in real-world battery life.