Welcome to GPSFileDepot!

Main Menu

Any recommendations?

Started by JGLTX, March 02, 2019, 07:17:08 AM

Previous topic - Next topic


The DriveSmart 61 (same hardware as the DriveTrack 71) is noticeably faster than any Garmin automotive model that I have seen. Going back a few years.... in 2010 I had a Nuvi 3790 which was Garmin's first glass screen multi-touch device. Nice unit, but definitely underpowered. Then I got a Nuvi 3550 in 2012 and that was much faster. I thought it was great, until I got a Dezl 760 in 2013 and it was faster still. The DriveSmart 61 blows it out of the water, in spite of the fact that the screen is 1024x600 and the Dezl is only 800x480. If you want to test your GPS, try this map. I doubt that anything older than a DriveSmart 61 will even work.

This is my system of putting raster imagery in an .img file. It's a simple grid of 48ft ft x 48ft (15m x 15m) polygons with a road and POI overlay. It works fine on my DriveSmart 61. A bit slow to initially render a view, but it can keep up at highway driving speed and has never crashed (although it disappears if you zoom out farther than .2 miles). This same map just crashes my Dezl 760. Didn't bother trying it on any of the older devices.

But the DriveTrack 71 renders raster imagery pretty fast - a lot faster than my Montana 600 for example. Initially it has to render it tile by tile, then as you drive, each tile is updated as needed, so there are always some small areas in the process of rendering at highway speeds. The farther you zoom in, the faster the screen updates (since there are fewer tiles). With 1-meter/pixel imagery, initial map rendering is very slow at a zoom setting of .3 miles. At 300 ft zoom setting, rendering is very fast. Anyway... for Garmin, it's fast. But, admittedly not as fast as raster imagery on my iPhone 6s Plus. ;)

Here's a screenshot from this morning, driving 50 mph with this map, performance was fine:

I used a "custom map" (.kmz file) for this, instead of Birdseye (.jnx). Actually, rendering speed felt about the same as birdseye. My understanding is that .jnx files can contain 5 zoom levels, but I haven't tried that yet (.kmz maps can only have one zoom level). So that will be my next test - if they really support multiple zoom levels, that should speed up rendering considerably (at the expense of file size). The .jnx files I have made so far only have a singe 1-meter level (this would be level 17 if using a format like .mbtiles).

BTW, if you enable City Navigator at the same time as raster imagery, there is very little impact on performance. I really only notice the difference when making a 90 degree turn, which causes a big screen update.


Looks good. Nice to know, that hardware is up to the task, even if there is no reason to use satellite view on a highway.


LOL - I suppose you have a point there, but it can help make a boring drive more interesting. :)

Also, since some people may not understand what "raster imagery" is, I think that needs clarification. It's a map that was created from an image. The image can be anything - such as a scan of paper map. So this is a way to use topo maps on the DriveTrack 71, and they work very nicely. Here's an example of a classic USGS 24k topo maps

And here is a 19th century topo

This is a modern topo map that I created

These examples are all from my site, but there are other good sources of free raster topo maps for just about any location. You can use the free Mobile Atlas Creator program (with Windows, Macintosh and Linux versions) to access these maps and convert them for the DriveTrack 71 (and dozens of other apps/devices). I have just updated my tutorial for this - see the following link:

Mobile Atlas Creator includes built-in access to free topo maps and aerial imagery from the USGS in addition to Canadian maps from Toporama. See Appendix A of my tutorial to learn how to access  "classic" USGS paper 24k topo maps. And these maps will work on all of Garmin's recent handheld GPS devices, not just the DriveTrack.

Now, Popej and I have had this discussion before, and I don't think he likes raster maps very much. ;) That's fine - they have their weaknesses (such as large file size, inability to search for features, etc). But they also have their strengths. Here in the US, many people consider the classic USGS 24k maps the "gold standard". And they also work across a broad range of apps and devices


BTW, you will need to use the scroll bar at the bottom of my post to see  all of these images, or right-click the image to open it in a separate tab in your browser.

Wouldn't it be nice if the GPSFileDepot forum software supported images wider than 500 pixels? I mean... it's 2019.  ;)


Quote from: Boyd on March 02, 2019, 09:18:42 AMThis model, and others from the past 3 or 4 years, displays them as ugly big "hearts" with no labels

Didn't realize this until I went on a long trip the other day, but they have changed the appearance of POI and waypoints on the DriveTrack 71. The icons are much smaller and they look a lot nicer. I wonder if they also made this change on the DriveSmart 65?


Yeah you need to add extra memory.