Why is the speed of writing to a flash drive jumping?

Question

USB flash drives

I have a Sony USM64RB USB 2.0 flash drive. Well, it's a very strange thing ...
The write speed jumps from 0 to 30MB / s.
Why is that?

CrystalDiskMark

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CrystalDiskMark 3.0.4 x64 (C) 2007-2015 hiyohiyo
Crystal Dew World : crystalmark.info
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* MB/s = 1,000,000 byte/s [SATA/300 = 300,000,000 byte/s]
Sequential Read : 43.247 MB/s
Sequential Write : 16.212 MB/s
Random Read 512KB : 41.453 MB/s
Random Write 512KB : 7.809 MB/s
Random Read 4KB (QD=1) : 4.676 MB/s [ 1141.5 IOPS]
Random Write 4KB (QD=1) : 1.023 MB/s [ 249.7 IOPS]
Random Read 4KB (QD=32) : 6.463 MB/s [ 1577.8 IOPS]
Random Write 4KB (QD=32) : 1.143 MB/s [ 279.2 IOPS]
Test : 500 MB [J: 41.7% (24.6/59.0 GB)] (x3)
Date : 2019/08/30 9:55:32
OS : Windows 10 Professional [10.0 Build 16299] (x64)

Answer 1

So it should be, the usual shitty flash drive.