Waypoints limits real or imaginary

[frankly frankie]

Before I took my issue to Garmin, my real, intended route with no waypoints would consistently fail to upload to my GPS at a shade under 5000 via points.  When they told me I must upload the matching map tiles, I found this increased the limit to almost 7500 via points. Oh, and that was after I had to re-create a large portion of my route in MapSource as it had been done in, oh, Bikely, I think.  Points clicked in Bikely didn't match up to points in MapSource.

[guess]
If a via point is present in a map tile, all that has to be stored is a reference to that point.
If a via point isn't present in a map tile, the GPS has to store a latitude, an logitude, and possibly an ID.
Presumably the matching would be done at upload time, since you could have created a route in Mapsource using a map tile that wasn't on the GPS.
[/guess]

Sounds plausible.

If you inspect the GPX as text, a Mapsource-created Route or Via Point has quite a lot of baggage, including Comment and Description fields which replicate some of the map info - eg "Albert Road and Victoria Drive".  On a mapless GPS this info is available, but as you say if maps are there maybe its matched at upload time.  Though in that case I'd expect Garmin to advise uploading maps before Waypoints, Routes and Tracks.  Which they don't, particularly.

BTW I've added to the files available at
http://www.aukadia.net/gps/
to include files to pre-load the GPS with User Waypoints.

I found that, taking a Legend Cx this time, just loading Routepoints I got a total of 2467.
By loading the max of 500 Waypoints first, then loading Routepoints, this was reduced to 1728 (or a total of 2228).  The User Waypoints have more baggage so appear to use more memory, on average, than Routepoints - but they do appear to be sharing the same memory allocation.

[MockCyclist]

[guess]
If a via point is present in a map tile, all that has to be stored is a reference to that point.
If a via point isn't present in a map tile, the GPS has to store a latitude, an logitude, and possibly an ID.
Presumably the matching would be done at upload time, since you could have created a route in Mapsource using a map tile that wasn't on the GPS.
[/guess]

My guess also - Garmin did say the tiles must be on the GPS for efficient memory usage.  It would be interesting to see what happens if a new gmapsupp.img is uploaded after a successful route upload.

I agree that User Waypoints and all the other types of point take the same memory space.  User Waypoint memory is used last.

My "final conclusion" result is as follows:

For a GPS Map 60 CSx:

Maximum number of unique points where there is no correlation to MapSource, ie, a route created in, say, Bikely:
3988 + 999 in User Waypoints totalling 4987.

Maximum number of unique points for a route created entirely in MapSource, no User Waypoints, all names generated by MapSource and all points placed on a map feature (road, junction, building etc.); and all corresponding map tiles uploaded to the gps:  7518

..... in that case I'd expect Garmin to advise uploading maps before Waypoints, Routes and Tracks.  Which they don't, particularly.....

They don't.    But then I don't understand why they say the GPS can store "50 routes of up to 250 points each" when it can't.  In fact it took Garmin US support to put Garmin UK support right on that point.

[frankly frankie]

But then I don't understand why they say the GPS can store "50 routes of up to 250 points each" when it can't.  In fact it took Garmin US support to put Garmin UK support right on that point.

Marketing English.

"Can store up to 50 routes"
and
"A Route can have up to 250 points"

would be a clearer way to put it, both those statements are accurate, at least.

Playing again this a.m. with the Cx, this time pre-loading it with a full complement of Tracks (20x500) and Waypoints (500) still left room for 2228 Routepoints - without much in the way of basemap incidentally - only 160 of those points were 'on the map'.  (I'll have a go with your file over the weekend MC - thanks)

In practical terms I don't see this as any sort of limitation at all.  A 18-day tour using a Route-a-day and about 100km a day, only required about 1400 Routepoints.   

[rogerzilla]

Autorouting really is limited to 50 waypoints, which is actually rather annoying.

[Greenbank]

Autorouting really is limited to 50 waypoints, which is actually rather annoying.

I can only assume some units are setup to 'Follow Roads' by default which is why people get problems.  Instead, set it up to 'Prompted' by default - in the Routing Setup page - then you always have the choice, if you get the 50 points error message, of choosing 'Off Road' and gaining the use of all 250 points.  And 250 points is a lot - even in the laniest country, that should get you 100 miles or more, in remoter country like mid-Wales, it would get you 300+ miles (if Wales were bigger!)

[Manotea]

I genarally use prompted + follows roads .

I use waypoihts sparingly, just enough to ensure there are no ambiguities in the preferred route, ie there is ony one way to get from a to b. But the real trick is to place the waypoints in the mlddle of roads on the route rather than peppering them across junctions or turns. This greatly reduces the number of waypoints  required as the GPS will guide you thru the complicated bits. Generally  I can describe a 200kn route  in <50 waypoints, ie one route file, so in practlse limits are simply not a problen

[rogerzilla]

The problem is that I set up the route using GMap or whatever and I don't know if the GPS will pick the "right" route until it's loaded and I've run a simulation.  Sometimes the stupid thing puts U-turns in if I haven't used enough waypoints.