On Wed, 2005-12-28 at 23:26 -0500, Peter Arremann wrote:
> Wrong. Several higher end boards for socket 939 chipsets can enable ECC.
Peter, you have a continual, nasty habit of not reading my _entire_
post. Revisit ...
1) Socket-939 Opteron *DOES* support unregistered ECC ...
"So if you want unregistered ECC, get a Socket-939 Opteron
If you want registered ECC, get a Socket-940 Opteron
If you want to use unregistered, non-ECC, get Socket-939 A64
The BIOS/POST/ACPI is going to be so configured, respectively,
on Socket-939 and 940 mainboards, depending on what CPU is
inserted."
2) I'm sure there are _some_ mainboards that support ECC on A64 ...
"There may be "hacks" to support otherwise on some mainboards,
but I seriously doubt it is well supported/reliable."
If AMD doesn't officially support it, please take that into
consideration. In other words, if a mainboard sets up the APIC** and
other registers to enable ECC for an Athlon 64, be wary that AMD does
_not_ test for it.
[ **NOTE: In my previous post, I _incorrectly_ stated ACPI when I meant
APIC. ]
> The only difference between Athlon64 and Opterons (940, not 939)
> is the registered part.
That's _not_ a difference in processor type, but _socket_ type.
Again, there are *2* variables ...
1) Socket-940 = registered, Socket-939 = unregistered *AND*
2) Opteron = ECC (AMD tested) and Athlon 64 = non-ECC (typical)
Again, there _may_ be Socket-939 mainboards that will setup the APIC to
enable ECC. But make no mistake, it's the CPU _itself_ that has the ECC
logic -- and if it's doesn't work, then you don't get ECC.
You can typically use (stability is another story) ECC memory in a non-
ECC system -- it just won't be ECC.
> MSI K8N Diamond Plus (manual page 3-11 for enabling ECC)
> ASUS A8N32-SLI Deluxe - QVL and spec sheet list both ECC and non ECC.
Yes, I've noted most of the new nForce4 SLI x16, which is basically a
commodity version of the workstation/server nForce Pro 2200+2050
combination, have this option. That's because they are AMD tested and
approved for the new Socket-939 Opterons.
Remember, just because it is in the setup/POST, doesn't mean the CPU can
support it. It wouldn't surprise me if all Athlon 64 processors have
ECC logic. But whether the Socket-939 versions are tested for it is
another story.
I've only seen ECC touted on the original Socket-940 Athlon 64/FX
processors.
> AMD Athlon64 spec sheet lists that both ECC and non-ECC modules are supported.
Again, be _careful_ on that statement, since there _are_ older
Socket-940 Athlon 64/FX processors. It all depends on the
_exact_revision_ and its features.
Remember, Socket-939 is _newer_ than Socket-754 and 940. And that
includes various changes to the core to reduce transistor count and
increase efficiency.
If you would be so kind to refer to which spec sheet/revision of the
Athlon 64, I will verify this for you. ;->
> Most low end boards do not have a way to enable ECC. Many don't work if you
> insert ECC modules. Most higher end socket 939 boards allow you to use ECC
The setup/POST may limit the APIC setup of ECC. But it's the CPU with
the actual ECC logic. ;->
--
Bryan J. Smith mailto:b.j.smith@xxxxxxxx
http://thebs413.blogspot.com
------------------------------------------
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