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    SubjectRe: [RFC] Documentation about unaligned memory access
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    dean gaudet <dean@arctic.org> writes:
    > on AMD x86 pre-family 10h the boundary is 8 bytes, and on fam 10h it's 16
    > bytes. the penalty is a mere 3 cycles if an access crosses the specified
    > boundary.

    Worth noting though, is that atomic accesses that cross cache lines on
    an Opteron system is going to lock down the Hypertransport fabric for
    you during the operation -- which is obviously not so nice.

    --
    Arne.
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