Re: [RFC PATCH] Btrfs: add sha256 checksum option

[Alex Elsayed <eternaleye@gmail.com>]

John Williams wrote:

> On Mon, Dec 1, 2014 at 3:05 PM, Alex Elsayed <eternaleye@gmail.com> wrote:
>> Incidentally, you can be 'skeptical' all you like - per Austin's message
>> upthread, he was testing the Crypto API. Thus, skeptical as you may be,
>> hard evidence shows that SHA-1 was equal to or faster than CRC32, which
>> is unequivocally simpler and faster than CityHash (though CityHash comes
>> close).
>>
>> And the CPUs in question are *not* particularly rare - Intel since Sandy
>> Bridge or so, the majority of SPARC systems, a goodly number of ARM
>> systems via coprocessors...
> 
> You can make convoluted, incorrect claims all you like, but the fact
> is that SHA-1 is not as fast as Spooky2 or CityHash128 on x64 Intel
> CPUs, and Murmur3 is faster on ARM systems. And it is not even close.
> Your claims are absurd.

And that _is_ the case; they are faster... *when both are software 
implementations*

And I'm not sure what is "convoluted" or "incorrect" about saying "Look, 
empirical evidence!"