Past Pro Loc: Spring Hill, Florida

When a Class10 card is purchased the buyer assumes he/she has gotten the best available. But, if you check the read/write speeds of various Class10 cards there are fairly great differences. Why would this be? A lower class card may be even faster than the 10, at least from my observations.

Also those four-letter designations: SD, SDHC and SDXC, I was under the impression (based on price) that the SDXC is greater, somehow, than the lowly SD. Well, it appears only that the SDXC is capable of being able to store more files, technology that allows more space in the same size card.

So, am I missing something important?

Dngallagher Loc: Wilmington De.

The CLASS designation rates MINIMUM speeds.... so a CLASS 10 card will read/write at a minimum of 10 MB/s...

There are many speeds for a "CLASS" 10 card.... from 10 MB/s up to 95 MB/s.

I do not pay any attention to the CLASS, but look for the UH rating and the actual read/write speeds of the cards, which can vary greatly.

Personally, I just picked up a Samsung Pro 32 GB card that is rated at 90 MB/s read and up to 80 MB/s write....most cards never talk about their write speed BTW and end up being half the READ speed they advertise.


Good link for card info based on your camera....

http://www.cameramemoryspeed.com/

Here is a link to a discussion on memory card speed here on UHH....

http://www.uglyhedgehog.com/t-268459-1.html

Good info when you dig into memory cards...

Past Pro Loc: Spring Hill, Florida

Thanks, DN you were very informative. I'll just have to really read what's on the card and not only rely on the class.

zigipha Loc: north nj

SD is only good up to 2GB, sdhc to 32 gb; sdxc to like 2TB.

Nothing to do with speed, but obviously the higher density devices thento use later technology which means faster.

I used sdxc but many computers don't support that natively (its a different interface than sdhc, which all computer support). yyou have to download drivers etc to support sdxc.

sdhc goes to 32GB. thats what i buy. Limits lost pics in case one goes kaput (forces you to change cards), and has bettter compatibility.

the whole class thing is, as was mentioned, meeting a minimum speed rating. but the fastest standard speed is class 10, which is 10mbps and is easily surpassed by most modern cards.

UH1 designation is also a minimum number, which happens to also be 10mbps. so no spec sheet difference.

there is no standard method to measure the speeds, so vendor comparison is caveat emptor.

I would look at reviews that do side by side comparisons and see what their benchmarkds say.

GENorkus Loc: Washington Twp, Michigan

I understood the different type had to deal with the method the data is stored on the card.

That has nothing to do with speed but everything to do with the quantity.

Rancher38 Loc: Halfway, OR

What find that chart is -- thanx so much (http://www.cameramemoryspeed.com/nikon-d810/fastest-sd-cf-card-speed-tests/)

Dngallagher Loc: Wilmington De.

It is... thats where I found the Samsung Pro 32 GB card I currently use - for 20.00 it is a speed demon that puts my 600x Transcend cards to shame. (they are in the spares case now)