261 of 272 people found the following review helpful
How to ensure your's is a genuine card,
You will most likely get a genuine card, but there are far too many fakes about so its essential you test your card on receipt to be sure, however some fakes will pass some of the test programmes, so test with ChkFlsh, Crystal Disk Mark & especially H2testW. H2testW tests the full capacity of the card, so will catch any using aliasing to fake larger than real capacity. A card with indicated capacity but high error rate/slow write speed indicates a 'ghost run' fake which won't last very long.
A 32GB card should have a formatted capacity of around 30GB, format in FAT/FAT32 only (NTFS shortens life of flash media & wont improve performance)
A class 10 card must have a write speed of 10MB/s minimum (large files) the first result in Crystal Disk Mark should indicate that. Cards are now appearing with the UHS-I class (marked with a 1 inside a U) these have higher clock rates so higher performance and are at least class 6 speed.
Read speeds should be over 12MB/s and getting toward 48MB/s on a USB3 UHS-I class reader with these.
If your cards speed test comes just below spec, that's a fail, don't assume 'close enough'.
SDHC cards have a maximum capacity of 32GB and SDXC a maximum capacity of 2TB but check your device is compatible with SDXC before choosing those over these SDHC cards.
Tracked by 7 customers
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Showing 1-10 of 14 posts in this discussion
Initial post: 13 May 2013 18:29:21 BDT
A. Davidson says:
many thanks for this guide/review I know there's lots of dodgy memory out there now I can prove it
In reply to an earlier post on 13 May 2013 20:34:42 BDT
Your very welcome.
If there is ever any doubt about a card, take photo's of both sides and send them to the manufacturer, most will be happy to authenticate or support any claim if fake.
In reply to an earlier post on 7 Jun 2013 04:50:14 BDT
R. E. Bond says:
Yes, i agree, great tips on buying a card. I can buy one now without problems... THANKS.
Posted on 23 Jun 2013 11:51:42 BDT
S. Naumovs says:
I am very grateful to Charles for such explicit comment. Absolutely everything you need to know about sd cards and beyond. Thank you!
Posted on 28 Jun 2013 01:32:00 BDT
Paul Price says:
Wow thanks for your advice. I've been trying to decide wether to pay up and buy direct from one of the big names or go 3rd party here and save a fair bit. Well thanks to your review I can now be confident in buying from Amazon.
Posted on 14 Oct 2013 13:01:47 BDT
M. Bhangal says:
Best way to guarantee a legit card IMO is to get the card in Amazon frustration free packaging. That way the card comes through Amazon and not some dodgy third party. I use my cards for 1080p video recording and have never had one from Amazon fail or look sketchy.
Plus the Amazon ones are usually amongst the most reasonably priced.
Posted on 29 Oct 2013 16:26:39 GMT
Last edited by the author on 30 Oct 2013 10:06:51 GMT
I did as per your advise, by testing this card via a MicroSD to USB converter, and upon completion of test, had this error. Can you advise?
Error reading file 'D:\1.h2w', offset 0x4600000.
(The request could not be performed because of an I/O device error. Code 1117)
Warning: Only 29962 of 29963 MByte tested.
Writing speed: 13.9 MByte/s
Reading speed: 18.2 MByte/s
---Addition to this post-----
Thanks for the valueable info. I raised the initial problem to Amazon and they admitted its a faulty card based on the information I provided to them, that was sold by Sunwood-UK. I wouldn't have recognised the problem otherwise and it would have only caused problem in long run.
Posted on 23 Nov 2013 11:55:32 GMT
Last edited by the author on 23 Nov 2013 13:28:26 GMT
Mr. T. White says:
Just want to add that I purchased from a marketplace seller here and I'm happy to say that the card passed as 100% genuine. Nonetheless...
Always ALWAYS ALWAYS TEST YOUR SD cards, PEOPLE!!! THAT'LL PUT AN END TO THE CHEEKINESS.
Here follow my results for the above card:
Warning: Only 29970 of 29971 MByte tested.
Test finished without errors.
You can now delete the test files *.h2w or verify them again.
Writing speed: 14.7 MByte/s
Reading speed: 18.1 MByte/s
In reply to an earlier post on 11 Dec 2013 10:50:40 GMT
This great advice. I shall pass it on to my friends. We wouldn`t have had a clue without this! Thankyou.
Posted on 28 Dec 2013 10:42:58 GMT
Jeremy Ritchie says:
Hi Charles, many thanks for this really useful advice.
I tried finding H2testW, Crystal and ChkFlsh for use on a Mac but discovered they are Windows only programs.
For those Mac users out there you can either run the Windows programs in BootCamp on a Mac or . . .
a guy in Brazil has developed a Linux version of H2testW that uses the same algorithm. It is called F3 and the details are on this page http://oss.digirati.com.br/f3/.
Not tried it yet as I have only just ordered the card! HTH