>Wow - there's some pretty unusual results in some of those >tests Howard... Thanks for the link. Quite noticeable >differences between different capacity cards of the same >type/spec... e.g. Suggests for the D800 a "SanDisk >Extreme Pro 95MB/s 8GB" is the best possible SDHC >card, offering a real speed of 42MB/s!
Right you are. Keeping in mind that the camera can only operate as fast as the slowest card, it's usually best to ensure that both SD cards are the same speed, or that the slot 2 card (writing a separate NEF or writing a backup or writing overflow from slot 1) is the faster one.
I personally use SanDisk Extreme Pro most of the time (the latest, fastest ones that is) and haven't had a problem.
I've also had very good results from Integral SD and CF cards for the past two years. Like SanDisk and Lexar, the Integral UltimaPro X cards have very good controllers and lots of multi-write, multi-level cell (MLC) NAND flash memory. SanDisk is basically getting SLC speeds and durability out of the newer type of MLC NAND flash. I think Integral may be using SLC NAND in its top-of-the-line cards, but there's no definitive confirmation of that at this time. It's all about the controllers anyway - the little circuit chip that controls I/O, deletion and cell erasure, and so on. SanDisk, Lexar, Integral and Transcend all seem to have the best controllers, and that makes their card reliability very high.
Kingston and other discount brands (made by the lowest bidder, somewhere), are terrible and rarely come close to meeting their specified speeds even under perfect lab conditions.
All of the old NAND flash memory on the market was usually more than fast enough for all of the 12.5 megapixel (or smaller) cameras. But the flash memory makers had to step up their game in partnership with Nikon, Canon and Sony as those 16+ megapixel sensors started hitting the market in large volumes. The D800/800e can still choke the life out of most cards, given the right circumstances. I doubt the market will cough up SD and CF cards fast enough to make the D800/800e really slick operators until late in 2014. The D7100, at 24 megapixels (and all the Canon and Sony competitors with similar size sensors) are only slightly easier on the fastest SD and CF cards. So I think we're dealing with a bit of a technology lag.
The Sony and Lexar XQD cards are speed demons for the 16 megapixel D4. The cards test in-camera at up to 90MB/sec which is exactly the sort of speed that would make the much higher megapixel counts of the D7100 and D800/800e a breeze to handle. But Nikon put the rarer, very fast XQD card format as a slot option in the D4 rather than the higher mp bodies. Go figure.
In 1991 or '92, I paid $820 for 16MB of SIMM RAM. I still resent it, but I needed that RAM. It was glacially slow, but it was the best available at the time. Of course a 60MB SCSI hard drive (with enclosure, power supply and controller card no less) ran me over $600 too, at the time. So a fast, 32GB SD card should be priced at around $1,679,360(!) based on that old SIMM RAM price. Seriously. My, my, my how times have changed for the better.