SanDisk 128GB Ultra microSDXC A1 UHS-I/U1 Class 10 Memory Card with Adapter, Speed Up to 140MB/s (SDSQUAB-128G-GN6MA)

This revu is for the 128gb SanDisk micro SDXC UHS-1 card, C10, U1, SDSQUAB-128G-GN6MA. I've given all the numbers so the reader will know exactly which animal we're talking about, as there is lots of room for confusion on these things. Anyway, I'm using this SD card inserted in an adapter which allows me to then plug the adapter in the standard USB port on my desktop computer. Most people stick these in their phone or camera but u can use them with your computer as well. So far this card is copying well. Copy speeds are nearly the same as my primary hard drive.Write speed, I mean...However, the benchmark read speeds are only a third as fast as the HDD, but that is not bad. This is what I see with all the other usb stick drives I've played with. I've suffered 2 usb stick drive failures this past summer so this little bugger comes to the rescue and is doing well. SD cards and usb stick drives have a controller, just like HDD have a hard disk controller, and if the disk controller is sub-par, the drive will not do well. This is often not taken into account. Whatever, we are having good performance with this so far. We examined the drive for a nearly 3 hours read-write test using CheckFlash, an old testing utility and it came thru with no error flags. Then we formatted using NTFS with 16k cluster size. I learned the hard way not to use small cluster sizes with SD cards or usb drives. They don't like it.. Oh, almost forgot.... This SD card came with NO FORMATTING. That was a surprise. Usually they are formatted FAT32 but not this critter. Blank and clean as a hound's tooth. No big deal. If you insert this in your phone, your phone should jump us and ask if you want to format the card, which naturally, you click YES, and then all should be fine.