I am using the most up to date version of lightroom and am tethered to a Canon 5d mark iii.
The catalog I am shooting to is 100% empty except for the images I am currently shooting. I have my cache set to 200gb as well. I am working with models and shooting on average about a frame every 2 seconds, yet the image doesn't show up in the catalog for about 10 seconds after I shoot a photo. It takes even longer as I continue to shoot. I'll do a burst of 20 photos, and lightroom gets bogged down. I will shoot tethered via the EOS utility, and images pop up immediately, so I can rule out the speed of the computer.
I need the images to pop up in lightroom much much faster and not sure what to do to make it happen.
On the 5d3 set to record RAW on the CF card and SMALL Jpg on the SD card. Then in the Canon menu select the SD card as the PLAYBACK card and then only the JPG files will be sent to Lightroom. See if this speeds things up enough for you. Its still not fast considering the JPG files are so small. Tether is not one of Lightroom best functions along with Book, Web and Slide Show and Face Detection.