Just to make the point about the inappropraitness of Tie::File for this.

  1. Using normal IO on a 400MB fastQ file takes 20 seconds:

    And use 1.3 MB of ram; performs 96e3 reads 97e3 writes; and consumes 42 billion clock cycles.

    Giving a projected runtime for the OPs 34GB file of 30.8 minutes.

  2. Using Tie::File on that same 400MB file takes 1340 seconds:

    And uses 601MB of ram; performs 10000e3 reads; 95e3 writes; and consumes 3,182 billion clock cycles.

    Giving a projected runtime for the OPs 34GB file, of 34 hours!

Tie::File has its uses. This is not one of them.

With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday'
Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
"Science is about questioning the status quo. Questioning authority".
In the absence of evidence, opinion is indistinguishable from prejudice.

The start of some sanity?

In reply to Re^2: Deconvolutinng FastQ files by BrowserUk
in thread Deconvolutinng FastQ files by snakebites

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