Fwd: AMD x2 chips

[Mark Hahn]

> But inside the A64 x2 or Opteron xx5, you have several ICs.  It

no, just one IC.

>  That really makes life easier for AMD.

you mean in the trivial sense that each core is replicated?  sure.

> I haven't researched if 1) each core gets a single DDR channel, 2)
> one core is wired with both DDR channels and the other core accesses
> it over HyperTransport or 3) neither core has memory directly
> attached, and accessed over HyperTransport where the actual DDR
> controller is at.  A few enthusiast sites report #3, but I've found
> many enthusiast sites to be incorrect.

none:
http://multicore.amd.com/Products/AMD_Opteron_Overview.pdf

the chip is based on a crossbar-like arbiter that connects HT ports,
DRAM controller and the cores.  the latter connect together, apparently.
they might be different ports on the crossbar, but they're definitely
not using HT, since a DC chip is a single HT "node" for addressing purposes.