GPS fix takes +30sec

I meant I synchronize with the Fenix 8 at least once per day usually in the mornings, but for this the Connect app is actively opened maybe 1-2min‘s. Then the app is still running but in the background and a bluetooth connection between the watch and the app is active probably all day. So there should be plenty of time to get the satellite data.  

If you want to determine whether your EPO / CPE is in fact up-to-date or not, this procedure worked on previous watches:

- From the watchface, hold UP for the menu

- Select System > About

- Scroll down until you see a screen that says “Ephemeris: Current” or “Ephemeris: Expired”. (Instead of Ephemeris, it may say EPO or CPE).

This screen should reflect the current status of your watch’s EPO / CPE, so you can try to narrow down the actual problem. (i.e. if it’s actually expired, you can try to investigate why that’s the case. if it’s actually current, then something else is going on.)

Sorry I didn't notice the link yesterday, thanks for hinting to that part of the Fenix 8 manual. Though as yesterday already discussed there is a sufficient connection to the Connect app so downloading satellite data shouldn't be the issue. I also looked up the System/Info part of the menu to see that the Ephemeris is up to date several times since starting to use the watch. I didn't look that up right before starting an activity though, but i don't think this would have displayed anything different. What i haven't tried is going out on an open area and staying there stationary for a few minutes. I find it a bit annoying though that such an expensive GPS watch is so sensitive doing what is one of its main features. Also i did a few hours of outdoor activities with GPS on and find it hard to understand why it is still taking such a relative long time to get a GPS fix.

Same here. My old Epix 2 takes about 5 sec. to get a GPS fix. My fenix 8 amoled needs at the same place and at the same time about 20-30 sec. All software is up to date. Garmin needs to fix this.

bluefish said:

In general, the almanac is only valid for a few days for all GPS devices

Few days are closer to 10 days (2 weeks?) based on my experience.

I have been reading 3-14 days from Garmin support for almost a decade, but I also read that technically 30 days of EPO/CPE data are sent to watches. So the validity depends on the storage logics of the GPS receiver unit.

I mean I supppse not all the SIRFstar, Mediatek, Sony etc. GPS chips stores exactly the same first X days of those 30 days of EPO/CPE data.

I am curious why not all the 30 days are stored? Are data  not precise enough for the let’s says 25th day?

EDIT: it came to my mind that my rusty GPSMAP 60csx asked me several times when it could not get a gps fix whether I moved 200 km or was the displayed date (time?) correct. So I looked for the handheld “EPO rules”, and found it gpstraining.freshdesk.com/.../24000035097-what-is-epo-or-cpe-on-a-garmin-product-

EDIT 2: pretty interesting discussion here https://www.reddit.com/r/Garmin/comments/hyg0l5/manual_gps_epobin_update_with_garmin_offline_for/, it seems that Mediatek provides 30 days, from which there are 28 days are real data.

Tisztul_A_Visztula said:

Few days are closer to 10-14 days based on my experience.

I have been reading 3-14 days from Garmin support for almost a decade, but I also read that technically 30 days of EPO/CPE data are sent to watches. So the validity depends on the storage logics of the GPS receiver unit.

No, it does not depend on the memory (our modern watches have gigabytes of memory - the CPE file cpe.bin is located in the "RemoteSW" folder).

Tisztul_A_Visztula said:

I am curious why not all the 30 days are stored? Are data  not precise enough for the let’s says 25th day?

If you take a closer look, the topic is somewhat more extensive.

The almanac is only one part of the whole thing. It is not very accurate and only gives a rough indication.

The ephemeris is also necessary to determine the position.

These contain more precise data from each satellite.
However, these are TOTALLY only valid for 4 hours.

This data can also be saved in advance.

With a GNSS receiver, a distinction is made between the following startup procedures:
1) Cold start
2) Warm start
3) Hot start
No data is available for 1)
With 2) the almanac is available, but no ephemeris
for 3) both are available.

I ASSUME that Garmin's CPE also contains the ephemeris in order to be able to make a hot start if possible. This is why the CPE is only valid for a few days TOTAL.

However, this does not mean that the file remains unchanged for (for example) 5 days and is then replaced by a new one. If the watch is continuously connected to Connect, the file is updated several times in order to always have the most accurate data possible. 

In this case, the CPE is usually always up-to-date and will never change to expired.

This enables a quick "hot start".

Tisztul_A_Visztula said:

Few days are closer to 10 days (2 weeks?) based on my experience.

I have been reading 3-14 days from Garmin support

I even suspect that it depends on the respective programmer how long the CPE is valid, because on the instinct solar it was valid for a maximum of 24 hours after a software update, which was fixed in the next FW after my report. After that it was valid for days again.

https://forums.garmin.com/outdoor-recreation/outdoor-recreation/f/instinct-solar/282962/instinct-solar---16-50-public-release-candidate 

bluefish said:

I even suspect that it depends on the respective programmer how long the CPE is valid,

It was what I meant as “storage logics” improperly. I wanted to express that it seems that technically 30 days were available, but for some reasons bot all of them were “stored” or let it call were “used”..