The buffer will allow the camera to do 10fps, it is the speed of the card which should determine how fast the buffer is cleared, and how long it can keep at that 10fps rate. Not everyone may need the 10fps for 200 images.
I posted this in the D5 thread earlier, which may be relevant to the D500, if it using the same electronics as the D500.
I read an article by Ole J Liodden about using the D5 to shoot 50,000 images.
This site goes into a bit more detail about the D5 than anything I have read yet
here. ISO performance seems very good, even using only Jpegs.
He talks of file sizes and use with a 95Mbs CF card.
"
File size (NEF uncompressed) on the Nikon D5 camera is 42-45 MB and 10-14 MB for jpg-files (highest quality)."
"The buffer capacity is also very good. With an «old» Sandisk Extreme Pro 90 MB/s card I can shoot 63 NEF-files (RAW Large) continuously, and it takes 23 second for the camera to write all files to the CF card and be ready for a new «full burst». With Jpg (highest quality) I get 163 continuous images (12 images / second) before the buffer is full, then it takes 15 seconds to write everything to the CF-card, and the camera is ready for another 163 series of images. The writing speed should be even better with newer and faster CF or XQD cards."
As you can see, he got 63 uncompressed RAW files (I'm assuming 14bit, but don't know for sure) with a 90mb/s CF card, so hopefully a similar speed SD will give similar performance on the D500. That is just over 6 seconds at 10fps. That would do me until I can get a XQD card, at hopefully cheaper prices than what they are going for now. If you want cutting edge though, you can pay the price for it.
I can't wait for some test results to start coming in.