Weird issue, which is more of a pleasant surprise. I ordered up one of these with my 5D3 a few months back, and it lets me fire off 13 frames in RAW before the buffer fills up and slows the camera down:www.bhphotovideo.com/c/product/646873-REG/SanDisk_SDCFXP_016G_A91_16GB_Extreme_Pro_CompactFlash.html
I purchased the exact same card, this time from Amazon, and this one lets me fire off 23 frames in RAW before the buffer fills up. I checked both boxes, and they are identical with the identical part number.
Interestingly, the box that the new card came in states that it's UDMA 6, but the card is labeled UDMA 7. That is the only difference in physical appearance between the two cards.
I'm not complaining that the new card is much faster than expected, but I'm just trying to figure out what's going on. To my understanding, UDMA 6 has a max transfer rate of 133 mb/s while UDMA 7 has a max transfer rate of 167 mb/s. Since the card maxes at out 90 mb/s, why should that even matter or impact writing speed?