K100D SD Card Write Speed Test

Here is a simple SD card write speed test with my K100D, for some SD cards of different brands and models, each of which has different rated read and write speeds, if any specified:-

Card and Identifier	Rated Speed	Chipset	Write Time for 3 PEFs (Rounded Up to the Nearest Second)	Throughput
EagleTec 256MB SD "SAMSUNG 334 K9K2G08U0M-YCB0 ULG023PX"	Nil	Samsung	17 s	1.79 MB/s
Lexar 1GB SD "LEXAR MEDIA SD1GB-120M 1405112 A040507B MADE IN U.S.A."	Nil	Lexar	12 s	2.54 MB/s
Toshiba 1GB SD "Toshiba SD-M01G 0508TJ8419L MADE IN JAPAN"	Nil	Toshiba	21 s	1.45 MB/s
Kingston 1GB SD "Toshiba SD-M01G 0514TJ9034L MADE IN JAPAN"	Nil	Toshiba	20 s	1.53 MB/s
KingMax 1GB SD "P01GS6GMHLLAG 651054"	18.8 MB/s Read, Maximum 15.4 MB/s Write, Maximum	Unknown	14 s	2.18 MB/s
Corsair 1GB SD 133X "S51GBA0615KKKT7TWN"	21 MB/s Read, Maximum 15.5 MB/s Write, Maximum	Skymedi	13 s	2.35 MB/s
Toshiba 2GB SD Class 4 "Toshiba SD-M02G 0642TK8283U MADE IN JAPAN"	4 MB/s Read and Write, Minimum 5 MB/s Write, Maximum	Toshiba	17 s	1.79 MB/s
Toshiba 2GB SD Class 6 "Toshiba SD-F02G 0706TL1531V MADE IN JAPAN"	6 MB/s Read and Write, Minimum 20 MB/s Write, Maximum	Toshiba	12 s	2.54 MB/s

As we can see, a faster card can help the K100D to write faster. However, the increase in performance is not as significant as it should be for such a very fast card used, e.g., the Toshiba Class 6 SD card rated at 20MB/s maximum write speed. Indeed, the K100D still writes rather slowly no matter what card used in it and it is indeed considerably slower than any of the DSLRs on the market. To compare, below are the results of the already slow Nikon D50:-

http://www.robgalbraith.com/bins/multi_page.asp?cid=6007-7905

But yet, the D50 is still relatively faster than the K100D.

Actually, if the same cards are put into a faster DSLR, there will be a huge difference in the write performance:-

http://www.robgalbraith.com/bins/multi_page.asp?cid=6007-8531

Do note that I have carried out my test with a very similar method as Rob Galbraith did and thus the results are quite comparable, I think. I shot 3 consecutive pictures in RAW and the read/write LED lamp's lit-up time is counted, by a stop watch and then the throughput rate for the write speed is calculated where 1MB = 1024^2 Bytes.

It is interesting to note that the claimed Class 4 "guaranteed" write speed by Toshiba according to the SD Association definition for a Class 4 speed card is actually somehow meaningless as the K100D is an example of such a slow device in which a 4MB/s rate can never be reached, so does the Nikon D50, too, although it is somewhere nearer.

In fact, the speed ratings of those SD cards are something that can never be totally trustworthy. In contrast, cards that are not rated may not be really slow, for example, the old Lexar ordinary 1GB SD card (bought in early 2005) has really given me quite a big surprise. It is actually quite as fast as the latest Toshiba 2GB Class 6 card rated at 20MB/s write speed (equivalent to 133X for the pre-"Class" representation), although it is actually not rated in any way.