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in reply to Re^2: problem of my multithreading perl script
in thread problem of my multithreading perl script

Take a look at an SSD review.

Note how the random 4k reads achieves a relatively low throughput (101.4MB/s in that particular case), whereas the throughput for sequential reads is considerably higher (431.8MB/s).

This is a common factor with all SSDs. Much faster than spinning rust, but it is still considerably faster to read a file sequentially than randomly.

If you are reading 12 files sequentially, concurrently, you are reading 4K blocks randomly from the viewpoint of the controller.


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