Intel QuickAssist Technology Zstandard Plugin for Zstandard

Re:Intel QuickAssist Technology Zstandard Plugin for Zstandard by ahofmann on Thursday August 17, 2023 @04:01AM (#37158571)

Why do they show different compression levels in their graphs? That seems kind of fishy to me.

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Re:Intel QuickAssist Technology Zstandard Plugin for Zstandard by pxeger1 on Thursday August 17, 2023 @05:53AM (#37159387)

Looks like they choose the levels to make the compression ratios roughly equal.

> For the Silesia corpus, data compression ratios are:

    QAT-ZSTD level 9: 2.76
    zstd level 4: 2.74
    zstd level 5: 2.77

This presumably also means the best possible compression that QAT can achieve is worse than what vanilla zstd can do.

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Re:Intel QuickAssist Technology Zstandard Plugin for Zstandard by klauspost on Thursday August 17, 2023 @07:20AM (#37159945)

.. for small payloads.

QAT cannot compress across blocks. So as soon as your input is more than 128KB the compression ratio tanks.

Usually well below what even level 1 of software zstd does. They choose the input very carefully.

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Re:Intel QuickAssist Technology Zstandard Plugin for Zstandard by mastax on Thursday August 17, 2023 @12:18PM (#37164026)

Interesting. That sounds basically perfect for ZFS where the default is 128KB blocks and zstd compression.

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