Rob Galbraith: CF Performance w/ the D70
According to Rob Galbraith:
"The Nikon D70's method of buffering photos before writing them to the CompactFlash card means that the card's write speed directly impacts the number of frames that can be recorded in an extended sequence. For example, in photographing the detailed, difficult-to-compress scene we use when benchmarking cards and cameras for this database, slower CF cards in the D70 limit the number of JPEG Fine frames shot sequentially to 9. Insert one of the faster CF cards, shoot the same scene, and the sequence limit jumps to 12-13 frames before the camera stops firing briefly."
If you haven't gotten a chance to peruse Mr. Galbraith's excellent database, it's highly recommended. He has tested most of the compact flash cards with all of the available DSLR cameras as well as some different card readers.