Very bad 4K read speed, any idea why?

Internal SSD SSD Plus
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crystaldiskmark.jpg

I replace the harddisk with Sandisk SSD Plus 240GB which I bought few days ago in my old samsung notebook NP350V5C. The notebook is running windows 10 Home 64 Bits version and the SSD is running in SATA 3. I have tried to use the Microsoft chipset driver, turn off the Windows Write-Cache Buffer Flushing, run windows safe mode. Any idea why the 4K read speed is so low? Thanks.

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I also run in high performance mode, check partitions are correctly aligned. All these cannot help.