What's the difference between these Micro SD cards?

Thank you for contacting SanDisk Technical Support. My name is Cornilius L. and I am here to assist you.

I understand that you would like to know what card is best for you. This is mainly depending on the device you intend to use it in and for what purpose you intend to use it.

The new UHS speed class 3 interface was officially released on Nov 6th by the SDA (SD Association). New Ultra High Speed (UHS) and Speed Class 3 (U3) symbol on SanDisk cards will indicate products capable of recording 4K2K video. The new UHS 3 bus on the card will allow fast 30 MB/s constant minimum write speed to ensure high-quality video recordings while the U1 allows minimum sustained write speed of 10MB/s. MicroSD cards can be used in a microSD to SD adapter without loss of performance. For more information on this new UHS 3 interface from this link to the SD association:

NEW SDXC AND SDHC MEMORY CARDS SUPPORT 4K2K VIDEO

The see what card is recommended for your device, you can check SanDisk’s online Product Compatibility Tool; this application allows customers to verify if the SanDisk product that they intend on buying is indeed compatible with their device. The application also suggests all compatible products for a wide range of devices.
That way you are always certain that the product you are about to purchase is compatible with your device.

Before testing the card we would advise to backup your data and format the card with the computer:
Formatting on a PC with disk management
Formatting on a Mac

You can test the performance of your memory card On Windows with CrystalDiskMark Benchmark Utility – which is a free application – from the direct download link below:
http://crystalmark.info/redirect.php?product=CrystalDiskMarkInstaller-en

For Mac, In order to test the speed of your product we would advise to download and run the BlackMagic utility from the Appstore which is a benchmarking tool specifically for Mac computers.

Please note that the best way to ensure you are purchasing an authentic SanDisk product is to buy from an authorized SanDisk reseller. You may view our distributor/reseller list to locate an authorized SanDisk reseller in your region:
Find a Retailer/Distributor

Upon purchase we would recommend providing the following information in order to register the product for warranty purposes:

- Exact model of the device
- Serial number (Take note of all the numbers that you can find on the device)
- Color of your device
- Capacity of your device
- Place of purchase
- Date of purchase (MM/DD/YYYY)
- Do you see the letter "R" or the word "Refurb/Refurbished" at the back of the device?
- How was the product packaged at the time of purchase?

Thank you very much for your interest in SanDisk products!


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Best regards,

Cornilius L.
SanDisk Technical Support

Thank you for your continued support. I think I know what's confusing me
now. I followed the link you gave to the SanDisk Extreme® PLUS
microSDXC™ UHS-I Card for Action Cameras

Selected: 64GB | Item # SDSDQX-064G

and when I put the same item # into Amazon.co.uk, this is what I get:
http://www.amazon.co.uk/SanDisk-SDSDQX-064G-U46A-Extreme-MicroSDHC-Adapter/dp/B00D6XTMFC/ref=sr_1_1?ie=UTF8&qid=1411409091&sr=8-1&keywords=SDSDQX-064G

Now it has the same Item#, but if you look at the image on the amazon
page it has a 1 inside the U, not a 3, this is what's throwing me off.
Is it a U1 or a U3 on the amazon page and maybe they are just using the
incorrect image? Is the one on the amazon page the same as the one
linked to by yourself?

Thank you for your update to the SanDisk Technical Support Team

U3 cards should be released in Europe before the end of this year. These cards will have the U3 sign and not U1. Sales and marketing of our resellers is independent from SanDisk. It is best to contact them directly for more information of what they have is stock as we are not aware of this.

For further information, we remain at your assistance. Thank you for your interest in SanDisk products!

Thsi is where my confusion is stemming from, the U3 DOES appear to be available on amazon.co.uk already, it says it's temporarily out of stock at present but it was in stock before so it must be due back in soon. The link to it is here:
http://www.amazon.co.uk/SanDisk-SDSDQXN-064G-FFPA-60MBps-Extreme-Adapter/dp/B00NMD4YCW/ref=sr_1_4?ie=UTF8&qid=1411547777&sr=8-4&keywords=64gb+u3

So this is where my confusion is coming from...

On the Sandisk link you gave me: http://www.sandisk.com/products/memory-cards/microsd/extremeplus-uhs-i-action-cameras/?capacity=64GB

It gives a item # SDSDQX-064G

And it states Extreme Plus 4K and has U3 on the card and states "Up to 80MB/s** read speed and up to 50MB/s write speed"


On the amazon.co.uk links, there are two confusing me:
http://www.amazon.co.uk/SanDisk-SDSDQX-064G-U46A-Extreme-MicroSDHC-Adapter/dp/B00D6XTMFC/ref=sr_1_1?ie=UTF8&qid=1411409091&sr=8-1&keywords=SDSDQX-064G

This gives the same item # of SDSDQX-064G-U46A and states 80MB/s so would appear to match the Sandisk page so far, but then it has a U1 in the image and also says it's U1 in the item description.


The next amazon one is:
http://www.amazon.co.uk/SanDisk-SDSDQXN-064G-FFPA-60MBps-Extreme-Adapter/dp/B00NMD4YCW/ref=sr_1_4?ie=UTF8&qid=1411547777&sr=8-4&keywords=64gb+u3

This gives a very similar, but not the same item # of SDSDQXN-064G-FFPA and is described as being only 60MB/s, and it isn't called the extreme PLUS, so would appear not to be the same as the one in the Sandisk link, but, it has the U3 stamp on the card in the image, says U3 in the title and mentions 4K video in the description, but then later in the description states "Thanks to its Class 10 and UHS Speed Class 1 (U1) ratings2, the SanDisk Extreme microSDXC UHS-I Memory Card lets you capture uninterrupted Full HD3 and 3D video."


So it appears neither links from amazon fully match the Sandisk link although the first link of the SDSDQX-064G-U46A seems to match everything but having the U3 mentioned. The stated speeds, the item# all seem to correlate to the Sandisk U3 link. I've searched the reviews (there's quite a lot) and there's no mention of U3 there either.

So is it a case that the amazon descriptions are incorrect, or that there's a lot of different choices with the Sandisk cards and they just don't have the one you linked to from Sandisk avaiilable on amazon (.com OR .co.uk, I've checked both) yet? Do the item #'s listen by amazon match other card options sold by Sandisk and match the amazon description correctly or is it likely that the first amazon link I provided will indeed be the U3 card?

Ok, I've just checked, and it appears not to be amazon exclusive, and on http://shop.sandisk.com/store/sdiskus/en_US/pd/productID.284149700/parentCategoryID.11442400/CategoryID.65981200 you'll see this appears to be the exact card that's listed on the first link I gave from amazon. This is the extreme plus with 80MB/50MB but is also listed as a U1 and the image is the U1, not the U3 as in the other Sandisk link....

So will the U3 be replacing the U1 and using the same item # or is it being sold as a different item #? It's very confusing and there doesn't seem to be a U3 extreme plus with 80MB/50mb speeds available on shop.sandisk.com or amazon?

Regards,

Hi again Cornilius,
Thanks for your continued support. Ok, I think I've finally understood.
So it's that the U3 are just new on the market, and they will be
replacing the U1, under the same SKU and it's just that the U3 hasn't
been rolled out fully yet and the U1's are still heavily stocked so will
be replaced as the stock diminishes so eventually we'll be seeing that
there will be two choices under the same SKU, a U3 and a U1, with the U3
Extreme Plus being the best card with similar read speeds to the U1, but
a sustained write speed of at least 30mb. At least that's what I've
understood from the latest mail. So it's just a matter of waiting I
guess for the U3 to be rolled out. Whether or not the U1 will be still
manufactured and sold under that SKU and the U1 and U3 will sell
simultaneously, I'm not sure, or perhaps the U3 will fully replace the
U1 under the same SKU and the U1 will just be phased out? Can you
confirm that the U3 will still work on any device the U1 will work on,
but the device just may not be able to utilise the full speeds if it's
not U3 ready?

At some point some of the new U3 cards will get a new SKU. We are not aware of exactly when, but you can expect it.

U3 cards are backward compatible with U1 devices. If your device supports minimum sustained write speeds of 30MB/s or higher, a U3 card is obviously the best choice as it will allow you to make cinema quality HD 4K video recordings.