Memory consumption is a way of life and with more cameras adopting the SD card format, you may need to stock up on some more media. Â Or you could just buy one of these and be good for a very long time. Â The Lexar 128GB Professional SDXC Card is currently the largest SD card available. Â Fortunately you don’t have to skimp on speed at this size since the card is 133x. Â At $250, it does carry a small premium although not as much as its SanDisk Extreme Pro 128GB CF counterpart.