Karenon 256GB Micro SD SDXC Memory Card High Speed Class 10 with Micro SD Adapter(D49-KR256)

My laptop tells me that Cardi's to slow.

My is Richard D. The reason I gave this card a 2 because of the performances. 1. 256 Gig Micro SD once formatted will give you 249 gig but will work or performed like 4 gig card. After following the corrected instruction and formatting the card and placing it in my Samsung Galaxy Note 8, this 256 GB Micro SD card started loosing data. I went a step further and try it in a different phone and the card did the same. I formatted again to my Go Pro and the card started to freeze. Then try formatted to my laptop and still I received 249 GB but would not allow more that 6 gigs on the card. Thats why I gave it a two due to the speedy service but the performance 1 because they didn't have zero on the scale. To other owners who cards works then congratulation but this didn't do the job.

It is NOT an SD SDXC Memory Card High Speed Class 10 as claimed/advertised. If they didn't claim that, I would give a 3-star. I attempted to use it for my camcorder, first set my Frame Rate to 60 fps and File Format to XAVC S HD, which requires an SDXC Class 10 card, but the camcorder rejected it and prompted me to change the card to a Class 10 card or change the camcorder setting to a lower rate.The good news is, it does work when I switched the camcorder setting to AVCHD and it does appear to give me 256GB although I have not tried to fill it up to see if it is actually capable of holding that much. And for $25, if you don't need high speed recording, it's not that bad.BTW, for $10-$20 more, you can get a true SDXC at eBay.

These cards are (or were, when I purchased) half the price of the other MicroSD cards available.There's a reason. They're too good to be true. Not worth it.I have tried copying over 114 Gigs of my iTunes library to the card I purchased....4 times I have tried. Reformatting each time.The one time it copied successfully, the computer recognized it as a "failed hard drive, copy off data and reformat immediately".3 other times the copy stalls out or the card shows up as "improperly ejected".Returning it. Don't waste your time or your money. Gonna have to spend more for the better card.

I purchased this card for use in my Nintendo Switch, which I've researched can take any microSD card. However, I had consistently run into a problem where I couldn't download more than 4 GB of games to the card before my system started running up with an error. Formatting (deleting the data) the card fixed it, so it led me to believe that the SD card could only hold 4 GB, and not 256 or the usual 249 that a formatted SD card of this size would hold. This is appalling, since it's 1/64 of the advertised capacity, and $26, currently $20,. Is an absurd price for such a small SD card.

Works OK with Windows / Mac OS but do not use in a Nintendo Switch, which was what I originally bought this for. The disk will work for about an hour and after that the Switch OS will report that it can no longer write to it.

Don't buy, sometimes going cheap is not a idea. Bought to use in a Note 9, bad idea, has been nothing but one big problem. Ordered a Samsung sd card yesterday, order cheap doesn't always pay.

I used it on my phone and it worked well for about 2 weeks then it stopped reading it. Even after formatting it the phone was not able to read the card.