Terrible! Once that microSD card is more than half full (let's say almost 2/3), the performance of that microSD card just slows down. At 70GB from 120GB, my write speeds started to average in kilobytes per second. s instead of MB/s. Below is an image of a performance test I just ran with an SD card. In principle, no operating system can save, read/write data. I will return this item as soon as possible. Some people will say it might just be my computer. I tested this on 4 different PCs. All had the same results.
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