Marty Cerven
Contributor
This issue has come up on the GoProuser forum, I was wondering why so many people have been having issues with SanDisk ultra c10 micro sd cards on the net. It looks to me like many are buying the Old Ultra cards which were not c10 but some dodgy retailers may be selling them as if they are, it could be an honest mistake but I highly doubt it as they are generally being sold much cheaper then the actual c10 cards. Its also possible people also are just misreading the product descriptions and assuming they are c10 when in fact they are just the old closeout models being cleared and so the cheaper prices.
I do have both versions as I bought a SanDisk 64GB Mobile Ultra microSDXC a while back when they first came out for my phone. Here is the old listing from where I bought it though it was much more when I got it having paid much more when it first came out and I use it in my phone.
Product no longer available - Scorpion Technology
This card doesn't say anything about c10 in the description but it is uhs-1 rated but had no class rating on it. The image on this link is the same as what the card I have looks like.
Here is my speed test of this card using h2testw.exe
download h2testw free and test flash memory « Fighting flash fraud on Ebay
I am just doing a 1000MB write and verify test as I know my cards are genuine. This program is also great to test if you suspect you have a card that is a fake, claiming to be higher capacity then it actually is that can be tested by doing a full test.
See the write speed 7.33MB/s this makes it not a c10 card and I knew this when I bought it but found it odd it had no class rating in the product description packaging or card itself. Also when the test starts up the first few seconds the card is only writing at just below 4MB/s so in reality its not even a c4 card as the rating is the minimum write speed and this is why sandisk most likely never put a speed rating on these cards.
Now here is the newer and current SanDisk 64GB Mobile Ultra Class 10
SanDisk 64GB Mobile Ultra Class 10 [SDSDQU-064G-UQ46A] - $79.00 - Scorpion Technology
though the pic linked on this page is the old card, as on the SanDisk site all the new c10 Ultra's dont say mobile anywhere on them. The new cards all look like this image below.
Also note the SD adapter on my old card doesn't say microSDXC but the new ones do.
Here is a pic of my 2 cards sorry for low quality pic I took it with my mobile and the lens is pretty scratched up and its macro mode sucks lol. Left is the new c10 card and the right is the old card as in the better quality pics I have also included.
Here is my speed test on this card, it also starts above 10MB/s and stays there throughout which is what a true c10 card is meant to do. My card reader is a USB3.0 reader so if your only using a USB2.0 reader the write speed will be below 20MB/s as this is a limitation of USB2.0
If doing a speed test using the GoPro as the card reader you will likely get a result like this. So if you dont have a card reader that is at least USB 2.0 running this test wont tell you if your card is up to the claimed spec or not. The GoPro camera's can even transfer at USB 2.0 speeds and this is one of the many reasons I dont use the USB port for anything other then charging, and I dont do this via PC but a powered USB adapter.
Why is this a big issue? well if the old Ultra starts writing at below 4MB/s this is only 32Mbps which is below many of the Hero3 black recording rates. Using Protune in 2.7k I have had rates up to 50Mbps which is 6.25MB/s if the card is below spec you will have nothing but troubles and using the higher bitrate modes most likely the camera will just cut out early into a recording or any time its write speed is below the video bitrate.
The Hero3 Black needs a genuine c10 card which means that the write speed will never fall below 10MB/s and if it does assuming the issue isnt down to your card reader you will have issues with it.
My first alarm bell came up when Amazon were selling the cards at prices below $40 for a 64GB SanDisk supposedly c10 micro sd card. Though I am not sure if those cards sold in the US on Black friday or cyber Monday were the old model I suspect they were.
Here is something I found searching for info on those specials.
If you note the model number of the old card in the discontinued link at scorptec is the same as this guy mentions SDSDQY-064G-U46SA
The current c10 64GB ultra's are SDSDQUA-064G for the Mobile version and SDSDQUI-064G for the camera version. I dont know the difference between the 2 and there is no difference in specs according to the Sandisk site and I have 2 of the mobile versions in my hero3 black cameras.
SanDisk Ultra microSDHC and microSDXCUHS-I Memory Card by SanDisk
SanDisk Ultra microSDHC and microSDXC UHS-I Memory Card with SD Adapter
Note neither of the new cards have Mobile written on them like the old card did. If you check the SanDisk micro sd page you will see all sizes of the c10 cards either mobile or camera models all have the same graphics, none of them say Mobile and if your card does then most likely you dont have a c10 card and you will have issues using this in your hero3 black edition camera's.
Micro SD Cards from SanDisk for Business and Consumer
The Amazon sale possibly could have been the legit c10 cards as its hard to find any exact info on that doing a quick web search. But it is also obvious via a few other peoples speed tests that they do have the old spec cards which are not c10 though they believe that is what they bought. Anyone with a SanDisk ultra card and having issues with it should run a speed test to ensure their card is what they think it is.
Your receipt should have your model number on it and if you dont have a receipt then the SanDisk lifetime warranty is not going to do you much good either.
I do have both versions as I bought a SanDisk 64GB Mobile Ultra microSDXC a while back when they first came out for my phone. Here is the old listing from where I bought it though it was much more when I got it having paid much more when it first came out and I use it in my phone.
Product no longer available - Scorpion Technology
This card doesn't say anything about c10 in the description but it is uhs-1 rated but had no class rating on it. The image on this link is the same as what the card I have looks like.

Here is my speed test of this card using h2testw.exe
download h2testw free and test flash memory « Fighting flash fraud on Ebay
I am just doing a 1000MB write and verify test as I know my cards are genuine. This program is also great to test if you suspect you have a card that is a fake, claiming to be higher capacity then it actually is that can be tested by doing a full test.

See the write speed 7.33MB/s this makes it not a c10 card and I knew this when I bought it but found it odd it had no class rating in the product description packaging or card itself. Also when the test starts up the first few seconds the card is only writing at just below 4MB/s so in reality its not even a c4 card as the rating is the minimum write speed and this is why sandisk most likely never put a speed rating on these cards.
Now here is the newer and current SanDisk 64GB Mobile Ultra Class 10
SanDisk 64GB Mobile Ultra Class 10 [SDSDQU-064G-UQ46A] - $79.00 - Scorpion Technology
though the pic linked on this page is the old card, as on the SanDisk site all the new c10 Ultra's dont say mobile anywhere on them. The new cards all look like this image below.

Also note the SD adapter on my old card doesn't say microSDXC but the new ones do.
Here is a pic of my 2 cards sorry for low quality pic I took it with my mobile and the lens is pretty scratched up and its macro mode sucks lol. Left is the new c10 card and the right is the old card as in the better quality pics I have also included.

Here is my speed test on this card, it also starts above 10MB/s and stays there throughout which is what a true c10 card is meant to do. My card reader is a USB3.0 reader so if your only using a USB2.0 reader the write speed will be below 20MB/s as this is a limitation of USB2.0

If doing a speed test using the GoPro as the card reader you will likely get a result like this. So if you dont have a card reader that is at least USB 2.0 running this test wont tell you if your card is up to the claimed spec or not. The GoPro camera's can even transfer at USB 2.0 speeds and this is one of the many reasons I dont use the USB port for anything other then charging, and I dont do this via PC but a powered USB adapter.

Why is this a big issue? well if the old Ultra starts writing at below 4MB/s this is only 32Mbps which is below many of the Hero3 black recording rates. Using Protune in 2.7k I have had rates up to 50Mbps which is 6.25MB/s if the card is below spec you will have nothing but troubles and using the higher bitrate modes most likely the camera will just cut out early into a recording or any time its write speed is below the video bitrate.
The Hero3 Black needs a genuine c10 card which means that the write speed will never fall below 10MB/s and if it does assuming the issue isnt down to your card reader you will have issues with it.
My first alarm bell came up when Amazon were selling the cards at prices below $40 for a 64GB SanDisk supposedly c10 micro sd card. Though I am not sure if those cards sold in the US on Black friday or cyber Monday were the old model I suspect they were.
Here is something I found searching for info on those specials.
Originally Posted by Variability![]()
![]()
This was on sale for roughly $44 CDN during Cyber Monday. I got it for $51 after taxes. I'm guessing it will drop again soon.
I think that was with PM with Best Buy... but unfortunately the model numbers are *slightly* different:
SDSDQUA-064G-U46A (Silver/red)
vs
SDSDQUI-064G-U46S
They should be the same card, except one has "Android" packaging and the other generic Sandisk packaging.
Lucky that your PM got through?
[Comp] Sandisk Ultra 64GB MicroSDXC - $59.00 Free Shipping from Amazon.ca - RedFlagDeals.com Forums
If you note the model number of the old card in the discontinued link at scorptec is the same as this guy mentions SDSDQY-064G-U46SA
The current c10 64GB ultra's are SDSDQUA-064G for the Mobile version and SDSDQUI-064G for the camera version. I dont know the difference between the 2 and there is no difference in specs according to the Sandisk site and I have 2 of the mobile versions in my hero3 black cameras.
SanDisk Ultra microSDHC and microSDXCUHS-I Memory Card by SanDisk
SanDisk Ultra microSDHC and microSDXC UHS-I Memory Card with SD Adapter
Note neither of the new cards have Mobile written on them like the old card did. If you check the SanDisk micro sd page you will see all sizes of the c10 cards either mobile or camera models all have the same graphics, none of them say Mobile and if your card does then most likely you dont have a c10 card and you will have issues using this in your hero3 black edition camera's.
Micro SD Cards from SanDisk for Business and Consumer
The Amazon sale possibly could have been the legit c10 cards as its hard to find any exact info on that doing a quick web search. But it is also obvious via a few other peoples speed tests that they do have the old spec cards which are not c10 though they believe that is what they bought. Anyone with a SanDisk ultra card and having issues with it should run a speed test to ensure their card is what they think it is.
Your receipt should have your model number on it and if you dont have a receipt then the SanDisk lifetime warranty is not going to do you much good either.