I am hoping someone might understand what’s going on here and be able to explain to me if my cards are fine or not.
I recently bought two 64gb micro sd cards (SanDisk Ultra) from Ebay, the seller’s called ‘atmemory’, he has an excellent rating & many sales. I’ve even bought from this seller before without issues.
I always like to test my sd cards before I put them to use, so I run FakeFlashTest, H2testw & CrystalDiskMark to benchmark them.
Well FakeFlashTest reports this
BAD MEMORY from sector 107859 (52.0MiB) to sector 77624659 (37,902.0Mib)
I get a similar message from the other card, only from 1000’ishMiB to 37,902.0MiB.
The thing is though, both cards pass h2testw with a write speed of 40MB/s & read speed of 80MB/s for the entire 64gb of storage.
CrystalDiskMark benchmarks results are also great, except for one of the cards that has extremely bad random 4k writes, like 0.008 MB/s. Those results look like this: http://imgur.com/IjUOhOf
I’ve also tried loading them up with 64gb worth of media and all the media seems to work fine.
So the cards work fine, the read/write performance is good too, except for bad 4K writes on one of them. So what’s going on with FakeFlashTest? Is the message a false positive or is there something fishy about my cards? Anyone got a clue?
I have tried to google the ‘problem’ hoping to find similar cases, but no luck there.
One other thing, when I run FakeFlashTest and it writes the ‘Marker Blocks’ this is done extremely fast on my previous cards, like a few secs per block, but on these new cards it takes a long time and looks like this:
And on my previous card that report nothing it’s fast and looks like this: