[CentOS] 64bit amd 3700++ and they don't want me to use ecc mem -- CPU, not mainboard

Thu Dec 29 01:30:05 UTC 2005
Bryan J. Smith <thebs413 at earthlink.net>

"Bryan J. Smith" <thebs413 at earthlink.net> wrote:
> The memory controller is on the _CPU_, _not_ the mainboard
> or its chipsets.  There are literally 368 traces on a
> Socket-939/940 mainboard to its DIMMs -- 2 sets of 184-pin
> DDR.

Let me clarify this, I mean there are literally 368 traces
from the CPU _directly_ to the DIMMs.  The Socket-939/940 CPU
handles all addressing, chip selects, etc...  There is *0*
logic on the mainboard itself for the memory -- the CPU
defines the memory support.

[ On Socket-754, there are only 184 traces, as it has only 1
DDR bank. ]

I.e., there is _no_ "Memory Controller Hub" (MCH) for AMD
Socket-754/939/940, which is Intel's term for the traditional
"northbridge" in Front Side "Bottleneck" (FSB) architecture.

Intel Socket-423 (DR), 432 (DR MP), 478 (DDR), 603 (DDR MP),
604 (DDR/DDR2 MP) and LGA-775 (DDR2) all use a MCH.  That
means the MCH defines the memory support, _not_ the CPU.


-- 
Bryan J. Smith     Professional, Technical Annoyance                      b.j.smith at ieee.org      http://thebs413.blogspot.com
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*** Speed doesn't kill, difference in speed does ***