Jim Rogers
New member
It has been almost steadily raining here on the East Coast of Virginia for a solid week. (7 OCT to 14OCT) To fill my time stuck inside, I experimented making brittles as well as using the Media Player on my Garmin units (Nuvi 765T and Zumo 660).
Sugar mixtures WILL burn at 306F, becoming very bitter and just plain nasty. Do a boiling water calibration check on your candy thermometer BEFORE use. Mine was reading 7F low and since the hard crack point of candy is 300F, the initial batches were inedible. Even my Bernese Mountain Dog, Miss Emm, would turn her nose up at them. Once the thermometer calibration check was performed, perfection.
On to the GPS units. Garmin states the max size SD card that can be used with the Nuvi 705 Series and the Zumo 600 Series is 8GB. 'Using an SD card size larger than 8GB is not supported for these devices. However, using one will not harm the device but it may or may not work. Also, Garmin supports all speed ratings (including unmarked cards)' (https://support.garmin.com/support/searchSupport/case.faces?caseId={a43e2650-1794-11e0-7efa-000000000000)
Garmin also states the maximum number of songs that can be placed on both the Nuvi 705 and Zumo 660 series is 2000.
(https://support.garmin.com/support/searchSupport/case.faces?caseId={a03da620-e588-11dc-d6fc-000000000000)
Since I had a 64GB micro SD card handy and could do nothing outside because of all the rain, after I made some peanut and some maple cashew brittle, I decided to do some testing just to see how far I could push the limits and under what conditions a very large SD card would operate best in my GPS units.
Gear involved in testing:
Mac Pro and MacBook Pro both running OSX 10.8.5 and iTunes 11.1.1
Sandisk microSDXC UHS-1 Card and Adapter formatted in MS Dos (32 bit)
Updated Garmin 765T - Discontinued - Uses standard SD card, used adapter with micro card
Updated Garmin Zumo 660 - Used mico SD card
PNY USB Card Reader used on the Mac Pro
Installed SD card reader used on the MacBook Pro
Results of testing on Garmin Nuvi 765T and Zumo 660:
Size
The maximum number of songs that can be read by the Garmin is limited only by the size of the SD card. However, the time it takes for the units to start-up is proportional to the number of songs on the card and, even more so, the arrangement of files/directories/subdirectories, not the size of the card.
Root Directory or Subdirectory/Directories
There is significant discussion on the web regarding the necessity to use subdirectories (and their size/number of songs included) or whether all the files/songs can/should be placed in the root directory of the SD card. In this test series, the SD card contained a total of 12, 822 items using a total of 47.83GB. Start up times are defined as from the moment the switch was placed to the 'on' position until the map appears, which coincides with when Browse is available in the Media Player.
With all files in the root directory, the 765T took ~48 minutes to start up while the Zumo 660 took ~24 minutes to start up.
With all files in a single subdirectory, the 765T startup time was reduced from ~48 minutes to ~34 minutes while the Zumo 660 startup time remained at ~24 minutes.
With all files in a total of 20 subdirectories (one off of the root (MP3) and 19 subdirectories that are a sub of MP3 of varying sizes between ~250 and ~850 files and no individual files in the root directory, the startup time for the Nuvi 765T is ~5 minutes and for the Zumo 660, ~4 minutes.
This series of tests resolves, at least for me, the question on the use of subdirectories. Ultimately, I plan to have a SD card set up with a directory off of the Root called MP3 then with the remainder of the music arranged in Artist subdirectories and in each of these a sub directory for each album.
Playlists
As might be expected, the time it takes to build a Playlist is proportional to the size of the Playlist. But their build time is also affected by the file structure; the better the files structure the shorter the build time. See the Root Directory or Subdirectory/Directories discussion above.
The maximum size a playlist that can be made on either of the units tested is 6584 songs, regardless of the number of songs on the SD card. This most likely is due to the limitations of the FAT32. This number was derived by loading 12,822 songs onto the micro SD card (47.83GB) and then telling the units to Play All. This effectively creates a Play All Playlist. As best I can tell, if the SD card contains more than 6584 songs/files, the Playlist will contain the first 6584 selected alphabetically by author. The build time for such a large Playlist is only slightly longer than startup time on both GPS units.
Artwork
Regardless of how meticulous I was ensuring the artwork was tagged to each and every individual song, I could not get artwork to consistently show in the Media Player. I evaluated artwork sizes; color profiles; varied the number of files and performed a host of other adjustments. Those that showed, showed and those that did not, did not. Since I cant really see the artwork well while riding, and should not be looking at/for it anyway while riding, I most likely spent way too much time trying to figure this one out. I guess it is just the anally retentive engineer in me. One thing to note, adding artwork will increase the size of the MP3 file. While this may be insignificant at the individual file level, when multiplied by the total number of songs on the SD card, it can end up being significant.
One final note on artwork, it did not show in the GPS unit's Picture Viewer. I suspect this is because artwork is part of the MP3 data and not a separate JPG file. I didn't really think they would show but had to try.
Transfer Mechanics
When connecting a Garmin to a PC/MAC with the SD card installed, the Garmin and the SD card will both mount and will mount separately. While it is certainly acceptable to transfer the songs/files with this set-up, this testing results reveal it can/will take up to five times longer for the transfer to occur with this arrangement when compared to using a separate card reader to transfer the songs/file to the SD card. Additionally, when I tried to transfer my entire 12,822 Master Riding Playlist from iTunes to an external source (SD card, USB HDD, etc) it would not be uncommon for me to get a file read/write error that would disrupt the entire transfer process. I found that reducing the number of files being transferred to groups of ~3,000 eliminated this problem.
GPS Performance
Other than the increased startup times, once the SD cards had been read, the units functioned normally on the road with no perceptible degradation in mapping/guidance performance.
Conclusion
If you are like me and find that regardless of how diligent you are you just cant seem to build your music/book list that will fit your changing mood while your are riding, don?t be afraid to use a larger than 8GB SD card. YMMV
Sugar mixtures WILL burn at 306F, becoming very bitter and just plain nasty. Do a boiling water calibration check on your candy thermometer BEFORE use. Mine was reading 7F low and since the hard crack point of candy is 300F, the initial batches were inedible. Even my Bernese Mountain Dog, Miss Emm, would turn her nose up at them. Once the thermometer calibration check was performed, perfection.
On to the GPS units. Garmin states the max size SD card that can be used with the Nuvi 705 Series and the Zumo 600 Series is 8GB. 'Using an SD card size larger than 8GB is not supported for these devices. However, using one will not harm the device but it may or may not work. Also, Garmin supports all speed ratings (including unmarked cards)' (https://support.garmin.com/support/searchSupport/case.faces?caseId={a43e2650-1794-11e0-7efa-000000000000)
Garmin also states the maximum number of songs that can be placed on both the Nuvi 705 and Zumo 660 series is 2000.
(https://support.garmin.com/support/searchSupport/case.faces?caseId={a03da620-e588-11dc-d6fc-000000000000)
Since I had a 64GB micro SD card handy and could do nothing outside because of all the rain, after I made some peanut and some maple cashew brittle, I decided to do some testing just to see how far I could push the limits and under what conditions a very large SD card would operate best in my GPS units.
Gear involved in testing:
Mac Pro and MacBook Pro both running OSX 10.8.5 and iTunes 11.1.1
Sandisk microSDXC UHS-1 Card and Adapter formatted in MS Dos (32 bit)
Updated Garmin 765T - Discontinued - Uses standard SD card, used adapter with micro card
Updated Garmin Zumo 660 - Used mico SD card
PNY USB Card Reader used on the Mac Pro
Installed SD card reader used on the MacBook Pro
Results of testing on Garmin Nuvi 765T and Zumo 660:
Size
The maximum number of songs that can be read by the Garmin is limited only by the size of the SD card. However, the time it takes for the units to start-up is proportional to the number of songs on the card and, even more so, the arrangement of files/directories/subdirectories, not the size of the card.
Root Directory or Subdirectory/Directories
There is significant discussion on the web regarding the necessity to use subdirectories (and their size/number of songs included) or whether all the files/songs can/should be placed in the root directory of the SD card. In this test series, the SD card contained a total of 12, 822 items using a total of 47.83GB. Start up times are defined as from the moment the switch was placed to the 'on' position until the map appears, which coincides with when Browse is available in the Media Player.
With all files in the root directory, the 765T took ~48 minutes to start up while the Zumo 660 took ~24 minutes to start up.
With all files in a single subdirectory, the 765T startup time was reduced from ~48 minutes to ~34 minutes while the Zumo 660 startup time remained at ~24 minutes.
With all files in a total of 20 subdirectories (one off of the root (MP3) and 19 subdirectories that are a sub of MP3 of varying sizes between ~250 and ~850 files and no individual files in the root directory, the startup time for the Nuvi 765T is ~5 minutes and for the Zumo 660, ~4 minutes.
This series of tests resolves, at least for me, the question on the use of subdirectories. Ultimately, I plan to have a SD card set up with a directory off of the Root called MP3 then with the remainder of the music arranged in Artist subdirectories and in each of these a sub directory for each album.
Playlists
As might be expected, the time it takes to build a Playlist is proportional to the size of the Playlist. But their build time is also affected by the file structure; the better the files structure the shorter the build time. See the Root Directory or Subdirectory/Directories discussion above.
The maximum size a playlist that can be made on either of the units tested is 6584 songs, regardless of the number of songs on the SD card. This most likely is due to the limitations of the FAT32. This number was derived by loading 12,822 songs onto the micro SD card (47.83GB) and then telling the units to Play All. This effectively creates a Play All Playlist. As best I can tell, if the SD card contains more than 6584 songs/files, the Playlist will contain the first 6584 selected alphabetically by author. The build time for such a large Playlist is only slightly longer than startup time on both GPS units.
Artwork
Regardless of how meticulous I was ensuring the artwork was tagged to each and every individual song, I could not get artwork to consistently show in the Media Player. I evaluated artwork sizes; color profiles; varied the number of files and performed a host of other adjustments. Those that showed, showed and those that did not, did not. Since I cant really see the artwork well while riding, and should not be looking at/for it anyway while riding, I most likely spent way too much time trying to figure this one out. I guess it is just the anally retentive engineer in me. One thing to note, adding artwork will increase the size of the MP3 file. While this may be insignificant at the individual file level, when multiplied by the total number of songs on the SD card, it can end up being significant.
One final note on artwork, it did not show in the GPS unit's Picture Viewer. I suspect this is because artwork is part of the MP3 data and not a separate JPG file. I didn't really think they would show but had to try.
Transfer Mechanics
When connecting a Garmin to a PC/MAC with the SD card installed, the Garmin and the SD card will both mount and will mount separately. While it is certainly acceptable to transfer the songs/files with this set-up, this testing results reveal it can/will take up to five times longer for the transfer to occur with this arrangement when compared to using a separate card reader to transfer the songs/file to the SD card. Additionally, when I tried to transfer my entire 12,822 Master Riding Playlist from iTunes to an external source (SD card, USB HDD, etc) it would not be uncommon for me to get a file read/write error that would disrupt the entire transfer process. I found that reducing the number of files being transferred to groups of ~3,000 eliminated this problem.
GPS Performance
Other than the increased startup times, once the SD cards had been read, the units functioned normally on the road with no perceptible degradation in mapping/guidance performance.
Conclusion
If you are like me and find that regardless of how diligent you are you just cant seem to build your music/book list that will fit your changing mood while your are riding, don?t be afraid to use a larger than 8GB SD card. YMMV
Last edited:
Of course good raw peanuts are essential.
