Re: [RFC] Documentation about unaligned memory access

[Arne Georg Gleditsch]

dean gaudet <dean@xxxxxxxxxx> 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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