Nikon D300s Dual Memory Slot Question

[michael_scharf]

<p>When using the dual memory slots on the Nikon D300s does it matter if the main card and backup card are the same speed? Also does the backup feature slow down the camera in general since it has to save it to two sources? I was looking at a 200x compact flash card which would seem to be fast enough for my shooting.</p>

[ShunCheung]

<p>If the two memory cards are in the backup mode, i.e. writing the same image files onto both cards to have two copies, the camera must finish writing to both cards before it can emtpy its memory buffer. Therefore, if the two cards have different write speeds, the slower one will determine the overall write speed.</p>

<p>My experience with the D300 (I have also tested the D300S but not extensively with daul cards) is that its memory buffer is deep enough that there shouldn't be any problems with shooting sports and action. In fact, I have never run into a "buffer full" situation in 3 years of using the D300.</p>

[daverhaas]

<p>Shun -</p>

<p>I've managed to fill the D300 buffer (using 20x cf cards) a few times - Baseball - shooting 1/500 sec - jpeg fine - to get a pitcher's full motion range and during swimming meets - shooting 1/320 - again jpeg fine - primarily at the start and turns.</p>

<p>Dave</p>

 

[ShunCheung]

<p>David, 20x CF cards are very slow in today's standards. If one shoots sports, I would make sure that the CF cards are UDMA compatible. 3 years ago I timed the D300, and it could empty one NEF file onto a UDMA-compatible CF card per second. I am less familiar with SD cards. They used to be slower than CF, but that might not be true any more for the fastest SD cards today.</p>

[frank_skomial]

<p>If you shoot NEF and JPG pictures, I would save larger NEF files to faster memory card, and smaller JPG to slower memory card.</p>

[eric_arnold]

<p>200x CF would probably be plenty fast. i believe the Lexar Professional series are 233x and the Sandisk Extremes are 300x or 60mb/sec; the Extreme Pros write at 90 mb/sec. with SD, they're getting faster but still lag a bit behind CF. i believe shun is correct that the camera cannot write faster than the slowest card.</p>