View Full Version : CF and SD cards.

3rd May 2012, 05:44 PM
Am I the only member to be confused by cards and the way their speed is measured? We have class this and class that, but what do they mean? Then there's xxMb/sec or yyyx. I use Sandisk but frankly have no clue as to whether what I've got is optimised for the E3, E5 and E620.

Is there a table somewhere that shows what all this means? More particularly can someone advise on what is the optimum card for each of the more recent E series cameras, both FT and MFT? There can't be any point in buying a card that will shift data faster than the camera can handle it.

jamie allan
3rd May 2012, 06:27 PM
The relationship between the speed stated in MB per second and the multiplier is a throwback to the days of the data transfer speed of a CD. The unit they used was 150kB/s in those days so a X4 CD wrote at 600kB/s.
So a 300X CF card is actually 300 X 0.150 MB/s = 45MB/s
a 200X is 200 X 0.150 = 30MB/s
a 133X is 133 X 0.150 = 20MB/s

I can't see any data in the manual of the E-3 or E-600 I have as to the maximum data transfer rate of the CF/PCMCIA interface. I'd assume that as CF card speed has continued to develop after the release of the E-3 there probably is a point at which a faster(more expensive) card isn't going to give you the bang for your bucks you hoped.
This may help http://kb.sandisk.com/app/answers/detail/a_id/31/~/sandisk-compactflash-read%2Fwrite-speeds-and-udma-information

5th May 2012, 09:25 PM
Bump! Can anyone else shed any light please?

5th May 2012, 11:23 PM
Bump! Can anyone else shed any light please?

Hi David.
Basically there is no simple answer. Card manufacturers are producing faster and faster cards quicker than the standardisation bodies can produce standards and different manufacturers employ different ways of expressing the speed of their products.

In the case of SD cards there is a Wikipedia article ; www.en.wikipedia.org/wiki/Secure_Digital which includes a table which shows some of this.
There is a similar article for CF cards www.en.wikipedia.org/wiki/CompactFlash but that is less helpful.:rolleyes:

As jamie said Olympus don't reveal the speed that their card interfaces run at so it's a matter of trial and error to some extent. I seem to remember that Ian recently reported some tests he did on different cards on the EM-5 but I think the results were not very conclusive. Sorry but I can't find the reference, probably in one of the "sticky" EM-5 threads.

Not sure if this helps or confuses, but I did try.:)


7th May 2012, 11:32 AM
I suspected it wouldn't be simple! The Wikipedia article is useful though.

8th May 2012, 06:09 AM
David, good thread with an interesting question - this subject has always puzzled me too!
I remember that I was quite disappointed when I shoved my then new 60MB/s SanDisk CF card into the E-30 and there was about NO felt gain in camparison to the 15MB/s or 30MB/s SanDisk CF cards I already had in use :(
Okay, I'll admit the 15MB/s card seems to be a tad slower in use. But in burst mode I will run out of camera buffer memory at once, no matter which card I use. From this observation I guess, the writing speed of the E-30 is somewhere in the vicinity of 20-25MB/s !?

Now I'll follow the provided links to SanDisk and Wiki, thanks guys *chr