Satellite fix is slow even on clear day and no obstructions. Is this normal?

From my experience - Yes.  The Mini does not store an Extended Prediction Orbit (EPO) file (as far as I know) so it is more like the much older watches that need to "search" the spectrum to find the current satellites  rather than have an up to date stored EPO to kick start the process that you have with all/most GPS watches now.  Bit more complex than this short description. Also, keep in mind that messaging is done through a different set of satellites - Iridium - as this is two way communications.  This is why you can have circumstances where GPS is good but it will take a while to get a message through (either way).  There was a thread on this a while back https://forums.garmin.com/outdoor-recreation/inreach/f/inreach-mini/191730/wait-for-gps----poor-gps-signal-performance 

Thanks a ton for your helpful and quick reply!  Does this unit use Iridium for all of its functions then or just for messaging?

The Iridium network is used only for messaging, sending "sent track points", SOS and so forth. The unit uses the normal GPS constellation for navigation.

Offhand, I don't know if razmichael is correct in assuming there is no EPO file usage on the mini. There is no status indicating whether or not the EPO file is up to date - which suggests but does not prove that it is not used.

As the referenced thread suggests, you should sync if you have not done so recently. IF the unit does use an EPO file, the sync will deliver an update if necessary.

IF the unit does not use an EPO file, then it does use coarse-grained almanac data delivered by the GPS constellation. It takes about 12 minutes in perfect conditions (clear view of the sky, unit stationary) to deliver a full almanac. So what you should do is take the unit outside, get a clear sky view, power up, set the unit down and let it "soak" for 20 minutes or so. This should allow the unit to download a full, up to date almanac.

Without a current EPO file OR a an up to date almanac, the unit would degenerate into a full sky search for GPS satellites. This can take some time, but it will acquire eventually.

Also note that moving the unit more than a couple of hundred miles while off (no fix for the duration) will make the almanac useless. The unit needs current time AND an approximate location to use the almanac effectively. The unit uses the last known fix as the approximate location. So the first fix after the move is likely to degenerate into a full sky search. It's not necessary to soak again - the almanac is valid and will be used once that first fix is established.

Tip: Be careful how you hold the unit while waiting for a fix. I once walked for 10 or 15 minutes with the unit in my hand, down at my side, with the antenna exposed and pointing upward. No fix for the duration. Your body is mostly water. Does a fine job of blocking GPS signals. And if the unit is still trying to download the almanac, it will take a LOT longer when moving. (There is a reason for that which is not worth delving into.)

See my earlier post in this thread. Try "soaking" the unit for 20 minutes with a clear sky view. This will acquire an up-to-date almanac. Without that, time to initial lock can be very long since the unit must do a full sky search.

You can try exchanging the unit as suggested by support. But I would try the soak first. Also, as a matter of good practice, I always wait for a lock after powering up and before I begin hiking.

Boosting the GPS fix by pairing with a smartphone is not a reasonable fix for the problem. If my phone has a signal, I don't NEED the Mini. If my phone has no signal and I  do need the Mini, the phone can't help.

And please do not double-post (in multiple threads) about the same problem.

The poor GPS performance of the inReach MINI is a very well known issue with no resolution available.

Hello, 

Thank you for your answer and sorry for the double post....

Concerning the pairing with smartphone signal, i was talking about internal gps chip capabilities of the smartphone which seems to be better than the IR 's one... it takes only few seconds to my smartphone to get a fix even if i m in Flight mode without celular network.

I will try your "soaking" method, but seriously, my goal is to take the IR with me in paragliding activities. When i go flying, i put on power my variogps and my Mini simultaneously: my vario gps takes less than 10s to be ready. I wanted to send a message with the Mini before take of and i had to wait more than 5minutes because of a poor gps reception: crazy: there is nothing above your head when you are on a paraglider's take of area!

The issue here is common to all GPS units. The almanac is coarse-grained information about the location of every satellite in the GPS constellation. With this information, the unit knows which satellites are overhead when it powers up. This allows it to acquire a fix quickly because it only "looks at" those satellites. Without an up-to-date almanac, the unit must do a full sky search. The time that takes depends on how many channels the chip can examine simultaneously. I don't know anything about the chip set in the Mini. But based on time to first fix on a cold start (without almanac or with stale almanac), it's not very capable.

Another potential approach is to use an EPO file. Think of this as a very long-lived almanac which is delivered to the unit in some manner other than via the GPS satellite constellation. IF the unit uses EPO (and I do not think that the Mini does so), the EPO file must be updated periodically.

Then there is so-called assisted GPS. This is the way most cell phone GPS systems work. There are lots of variations, including augmented use of any on-board GPS chip (in the phone). Some variant on this (including storing almanac data on the phone) is probably what is happening with your smart phone.

https://en.wikipedia.org/wiki/Assisted_GPS

My point here is that the Mini depends entirely on the almanac acquired from the GPS satellites. Once the initial almanac is acquired, the unit will automatically update it when it is powered up and has a decent sky view. Note that moving the unit more than a few hundred hours while off invalidates the almanac since it is location-specific. But aside from that, one initial soak and you should get much better time to first fix from then on.

While all of that is true, I have personally experienced the inReach MINI frequently losing satellite fix even after many hours into a single trip, all the while the other Garmin GPSr I am using simultaneously never lose their satellite fix.

This is not an almanac issue. This is a hardware failure. Worse yet, it appears to be a design issue that can not be resolved with firmware updates or replacement units.

The Mini is definitely more prone to loss of fix, as well as slower to acquire, than any GPSr I've ever seen (going all the way back to the GPS III+). I'm only addressing acquisition here. However, having an up to date almanac on board will also speed up re-acquisition after loss of fix.