By: EduardoS (no.delete@this.spam.com), November 1, 2008 11:15 am
Room: Moderated Discussions
Michael S (already5chosen@yahoo.com) on 11/1/08 wrote:
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>I think there is some mistake in their measurement methodology. It is damn hard
>to believe that 64-bit moves have higher throughput than 32-bit moves.
The problem with 64-bit moves are alignment and bank conflict, K-8 banks are 8 bytes wide, two sequential 32 bits stores results in a bank conflict.
>Right now I have no access to K8 running 64-bit OS.
>Give me couple of days, I'll test that when back at work.
Even a 32 bits SO will be fine, just make sure each store is separated by 8 bytes and they are aligned, I did it here, it works.
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>I think there is some mistake in their measurement methodology. It is damn hard
>to believe that 64-bit moves have higher throughput than 32-bit moves.
The problem with 64-bit moves are alignment and bank conflict, K-8 banks are 8 bytes wide, two sequential 32 bits stores results in a bank conflict.
>Right now I have no access to K8 running 64-bit OS.
>Give me couple of days, I'll test that when back at work.
Even a 32 bits SO will be fine, just make sure each store is separated by 8 bytes and they are aligned, I did it here, it works.
