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On 20/10/2017 18:15, Michał Górny wrote: |
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> W dniu pią, 20.10.2017 o godzinie 17∶42 +0200, użytkownik Paweł Hajdan, |
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> Jr. napisał: |
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>> Curious, do we have any measurements/estimates of the performance cost? |
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> |
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> With a single thread serial processing of all hashes, it's just sum of |
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> times involved in every hash, i.e. Th = T1 + T2 + T3 + ... You'd have to |
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> get some numbers to get something smarter out of it. |
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> |
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> If we assume we can do N threads, then cost of N algorithms is equal to |
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> the slowest of them all. Which implies that having N algorithms is |
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> fastest on systems capable of at least N threads. |
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> |
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> Taking a random comparison [1], it seems that SHA3/512 is 3-5 times |
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> slower than SHA2/512. |
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How large part of dependency calculation / other portage's operation is |
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this though? |
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My point is, did profiling turn out hash computation as bottleneck, or |
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is this more speculative? |
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I'm still in favor of modernizing the hashes, just somewhat skeptical |
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when performance is being mentioned. |
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Paweł |
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