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Avernar

Does the eTrex 30x support GGZ?

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Title says it all.

 

Note: I'm asking about the 30x and not the 30.

Edited by Avernar

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Page 43 of the manual would lead one to believe it does not, but I never trust the Garmin manuals to be either correct or complete. Garmin is never consistent on the data it supplies for its units. An example that is frequently missing is the number of caches a model will hold. You can usually find the information some time after product release but often not on the spec page for the unit. Sigh...

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Garmin is never consistent on the data it supplies for its units. An example that is frequently missing is the number of caches a model will hold.

Yeah. I've always had to hunt for that number and filter out all the people quoting the waypoint limit.

 

I was hoping someone had one as Garmin's website also led me to believe it didn't. The units that have GGZ seem to have "250,000 preloaded geocaches" on the page somewhere.

Edited by Avernar

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Bringing back from the dead as I just bought one.  They do not appear to be able to read GGZ files.  It sounds strange, but it seems to be the case.  What is really weird is there is a Garmin/GGZ folder.

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46 minutes ago, MaliBooBoo said:

So the only difference between the 30 and the 30x is a higher resolution screen?

and more internal memory, and faster processor, and maybe a different antenna. There are hardware differences that aren't necessarily visible from the list of features.

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Even my old Oregon 550 has a empty \Garmin\GGZ folder. I have no idea how it got there. It is not something I consciously created or tried to use as I know the old Oregon does not support GGZ files. My guess is that something in GSAK created it. Perhaps I had a wrong option checked in one of the GSAK functions or macros at some point in time, but if that is the case I don't remember it.

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7 hours ago, speakers-corner said:

Is there a GGZ-Folder on your 30x? Have you tried making a GGZ-File with GSAK and then copying it to that Folder?

Yes.

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1 hour ago, alandb said:

Even my old Oregon 550 has a empty \Garmin\GGZ folder. I have no idea how it got there. It is not something I consciously created or tried to use as I know the old Oregon does not support GGZ files. My guess is that something in GSAK created it. Perhaps I had a wrong option checked in one of the GSAK functions or macros at some point in time, but if that is the case I don't remember it.

Yes, this folder is automatically created if you use the GarminExport macro in GSAK. Even in units which don't support GGZ.

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1 hour ago, MaliBooBoo said:

Surprisingly minimal update. Still shocking to me that Garmin couldn't be bothered to add GGZ to the 20x/30x.

The hardware in the eTrex line is still underpowered compared to the gpsMap and Oregon/Montana lines. Even with the advantages of GGZ, it still likely takes more processing power and RAM (do these have separate RAM from the internal flash storage?) to deal with the unlimited geocache storage that accompanies GGZ support.

The eTrex line has always meant to be a less-featured, less durable introductory GPS compared with the more advanced models. I always say that the eTrex are toys while the gpsMap and Oregon lines are tools.

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Bumping this thread with a little more information because it was referenced elsewhere. Since this thread was started, we now know that the 30x does indeed not support ggz. Mineral2's final sentence is a little harsh - let's call the "budget" or "entry" models instead of toys, but I think the distinction is fair.

With more than a casual understanding of how geo formats work and being able to probably draw a coarse block diagram of them from, I think that Mineral2 hit the root cause on the head.  It's probably not an absolute limit but a practical one of how slow the product can be and still be considered usable. The recipes for making computers fast are well understood. Line one starts with "cost" 🙂 If your $150 unit took 2 minutes to draw a map refresh when you moved the cursor or 20 minutes to do a search, is it actually reasonable to say it "supports" something when your $600 units can do each of those 60x faster? So there's probably a practical (and artificially enforced) limit on the cheaper models. From our experience building Google Earth, we know that drawing 5,000 icons, with labels, and trying to enforce what gets drawn on top of each other while keeping 60fps is hard. 

To Mineral2's specific musings, RAM is different than internal flash and even internal flash is segmented into the parts you can see (the stuff that shows up when you mount the volume over USB) and the parts you can't that stores the code, settings, fonts, sounds, a version of the user data that's fast to display and search, and such. Memory is a hierarchy of speeds and size, with each run of the ladder representing at couple dozen orders of magnitude. Variations of https://people.eecs.berkeley.edu/~rcs/research/interactive_latency.html might help people understand why having enough RAM to hold a table in memory instead of fetching from even parallel flash can easily be 1500x as fast.  (A battery operated computer in your pocket is closer to the turn of the century than the data centers used as the inspiration for that chart, but the few people that read my longer writings may still find it helpful to visualize why their phone has 2GB of RAM and 128GB of flash any why programs will work so hard to read one scarcely.)

For a fun way to reason how GPSes *probably* store things internally, https://jimkang.com/quadtreevis/ does a very accessible demonstration of an important data structure called the quadtree. (This IS how Garmin's POI format works...) Tinker with it and you can see why it works well with large spatial data sets and why it's super fast to read or display on a map at varying zoom levels and a real pain to change. That's almost certainly the reason there is no "edit/add geocache" page on your Garmin. 

 

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