Extremely slow Read/Write SanDisk 400GB Extreme microSDXC UHS-I/U3 A2 Memory Card

Someone said the following methods can promote the read/write speed of your SD card. But I’ve tried this to no avail. Maybe it will work for you! Open Device Manager and select Disk Drives. Find your thumb drive in the list and right click on it. Select Properties and then Policies. Finally, Select “Better Performance”.