new 32gb ultra class 10 UHS-I disconnects under pressure

I purchased a 32GB Ultra UHS-I Class 10 Micro SDHC Card a few days ago **(SDSDQUA-032G-U46A)**and I’m having problems.

I’ve tested via a USB 2.0 Port with the card in an official Sandisk Micro USB Adapter.

  1. Testing with h2testw results in the speed dropping from 11MB/S to 5.7MB after a prolonged period of time when doing a full capacity test.

  2. Copying 28GB worth of files in one copy session to the card using Windows 7 results in the copying transaction failing after it’s half way though almost as if the card becomes prematurely disconnected.

  3. The card gets very hot.

  4. Testing the card using the SD Card adapter results the card in transferring files at no more than 5MB/S however it doesn’t randomly disconnect.

  5. I already own a 8GB Ultra Micro SDHC UHS-I card which works fine and gives me consistent transfer speeds of 16MB/S Write 18MB/S read using the official Sandisk Micro USB Adapter via the same USB 2.0 port.

I’ve been happy with my 8GB card and based on the performance of it I opted to buy the 32GB version however the problems I’m facing with the 32GB card are very frustrating.

1.How can I resolve these issues?

  1. Do I simply need a replacement or should I return to retailer and opt for a better card?

  2. Can you guys recommend a more robust and reliable card?

  3. Is this an SDXC card or an SDHC Card as per the packaging?

if the card is getting hot it should be replaced. 

Hi I received a replacement card.

I haven’t stress tested the replacement card yet however I’ve noticed slow speeds again.

I already own a 8GB Ultra Micro SDHC UHS-I card and performed a comparison test.

Here are the test results using the same test scenario in ATO benchmark and H2testW. Both cards are being used in a USB Micro SDHC Card reader via a USB 2.0 Port.


8GB Ultra Micro SDHC UHS-I card

Read = 18 MB/S

Write = 16 MB/S

32GB Ultra Micro SDHC UHS-I Card

Read = 19 MB/S

Write =  10 MB/S

Why is it that the 32GB card is giving a slower write speed? Occasionally the write speed did go up to 16MB/S for a few seconds but predominantly stays around 8-10 MB/S.