I recorded a rehearsal at a remote location using a Zoom R16.  I want to move the 8 tracks over to Sonar.  The tracks are huge, lasting over 4 hours (I just turned on the recorder and let it run).  The R16 records data on SDHC cards.  So, I remove the card, plug it into my computer's card reader, select the file I want to import into X3 and it goes to work.  I did not time the transfer, but I estimate it actually took longer than the 4 hours of audio that is on the track.  But the track did get imported into X3. At this rate, it will take me days to transfer 8 tracks. 
 
Tomorrow, I will start actually recording in Sonar as I play back the audio.  At least I can record 2 tracks at once, so I will need only to run 3 more passes.
 
Can this be right?  Any suggestions? 

I would have transferred the files to the hard drive first, then imported them into Sonar.
 
Sonar will have a harder time reading and importing from an SD card than from a hard drive due to transfer speed.
 

The bottleneck may be a USB 2 card reader. If this is going to be a common thing, you might want to get a USB 3 reader. That assumes that you have a USB 3 port on your computer. Many internal readers are actually connected to a USB header on the motherboard, and it is commonly USB 2 even if you have USB 3 ports on the board.

Is the SD card a type 10? They are faster. And does the Zoom have a USB port? that would also be faster. And I agree with just drag and drop the files to your computer first. 
 
Wave lab or an audio editor that does multi track would open those files within a few seconds. Sonar is slow because it renders the file int it's format. It might be faster if your project is set to same format as the Zoom ( if possible) 
Cut and paste each song to Sonar. 
I've not done 8 tracks but my Tascam DR 40 does 4 tracks and this is what I do with big files. 

Ruben
I would have transferred the files to the hard drive first, then imported them into Sonar.
 
Sonar will have a harder time reading and importing from an SD card than from a hard drive due to transfer speed.
 

Agreed.  Transferring huge files from SD cards can be very slow, especially when the system is busy doing other things as well... I'm pretty sure that once you get the files onto your hard drive, SONAR will have no issues importing them.

You may also be accidentally (or purposely) sample rate converting at the same time.