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 at ieee.org http://thebs413.blogspot.com ------------------------------------------ Some things (or athletes) money can't buy. For everything else there's "ManningCard."