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2007/6/28, Daniel Gryniewicz <dang@g.o>: |
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> |
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> On Thu, 2007-06-28 at 18:45 +0200, Dieter Ries wrote: |
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> > Hi, |
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> > |
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> > |
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> > Hemmann, Volker Armin schrieb: |
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> > > On Donnerstag, 28. Juni 2007, Simon Cooper wrote: |
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> > >> whats with the NUMA stuff? |
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> > > |
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> > > nothing. If you only have once cpu with two cores, don't use it! |
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> > |
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> > What exactly does that mean? None of those : |
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> > |
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> > [*] Non Uniform Memory Access (NUMA) Support |
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> > [*] Old style AMD Opteron NUMA detection |
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> > [*] ACPI NUMA detection |
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> > [*] NUMA emulation |
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> > |
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> > Or should one use the emulation. |
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> > |
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> > And is it suggested not to use NUMA only on amd cpu's, or is it just the |
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> > same on core2duo processors? |
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> > |
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numa is a way of using the integrated dma ram controllers of amd64 cpus.... |
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on intel systems they are useless if you don't have a lot of cpus.... |
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> BTW, what is NUMA exactly? And when should one use it? |
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> > |
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> |
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> Intel CPUs don't do NUMA, only AMD cpus do. However, you need at least |
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> 2 physical CPUs to actually do NUMA, and you also need memory attached |
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> to each one. Most cheap dual CPU AMD boards don't actually have memory |
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> hooked to both CPUs, only to one of them. If your board has banks of |
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> ram (generally on either side of the CPUs) it probably does NUMA. |
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> Otherwise, it doesn't. |
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> |
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> That said, enabling NUMA on a non-NUMA box doesn't really hurt, same as |
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> enabling SMP on a non-SMP box. |
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of what i have experienced on my amd64x2 4800 i had little performance boost |
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when i used numa compiled.... for what i know on the amd x2 cpus every core |
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has its own l2 chache, its own 64bit ddr mem controller and a unique l3 |
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cache.... i have learned that the numa helps the overall system performance |
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by using in a better way the integrated mem controller and not only by |
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working as you said, but i may be wrong.... the only fact that i've |
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experienced on my desktop is that i have a little perfomance boost.... it |
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may be due to the mb, an Asus M2N-SLI Deluxe AiLifestyle Series.... |
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Daniel |
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> |
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> -- |
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> gentoo-amd64@g.o mailing list |
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> |
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> |
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-- |
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beso |
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d-_-b |
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