Write speeds of memory cards - DPChallenge Forums

Olympus OM-D E-M5 Mark III

04/07/2010 10:38:24 PM · #1

I am assuming the larger the number the better? for example I see 60x and 133x for write speeds. Then I see class 4 or class 6. Now I see class 10! I am looking for some new SDHC cards for the next camera I purchase. Looking for a little info. Any thoughts?

Yo_Spiff

Olympus 12-100mm f/4.0 M.Zuiko ED IS PRO

04/07/2010 11:21:41 PM · #2

The class rating is more directly meaningful and corresponds to the minimum throughput. Class 6 can do up to 6MBps if the device it is attached to is capable.

From Wikepedia:
Speed Class Rating

The Speed Class Rating is the official unit of speed measurement for SD Cards, defined by the SD Association. It is equal to 8 Mbit/s, and it measures the minimum write speeds based on "the best fragmented state where no memory unit is occupied":[8]

The following are the ratings of some currently available cards:

* Class 2: 16 Mbit/s (2 MByte/s)
* Class 4: 32 Mbit/s (4 MByte/s)
* Class 6: 48 Mbit/s (6 MByte/s)
* Class 10: 80 Mbit/s (10 MByte/s)

Message edited by author 2010-04-07 23:23:48.

giantmike

Canon EOS R6

Canon EF 100mm f/2.8L Macro IS USM

04/07/2010 11:29:14 PM · #3

For actual speed tests, I have found this site indispensable: //www.robgalbraith.com/bins/multi_page.asp?cid=6007

04/07/2010 11:30:38 PM · #4

Thx Spiffy I didn't think to check Wiki for that 411

Nikon AF-S DX NIKKOR 18-200mm f/3.5-5.6G ED VR II

04/07/2010 11:31:46 PM · #5

Originally posted by giantmike:

For actual speed tests, I have found this site indispensable: //www.robgalbraith.com/bins/multi_page.asp?cid=6007

Thx for your link Mike

Adz

Nikon D80

02/15/2011 06:37:49 PM · #6

I know this is an old thread, but was wondering why this this class 4 card is the same price as this class 10 card?

Is the class 10 card cheap because it's unreliable or something?

Message edited by author 2011-02-15 18:38:14.