The memory support depends mostly on the CPU but the motherboard must support ECC and/or registered memory to work with it. Late Asus boards have the best support for ECC and large modules.

Some CPUs memory controllers are just plain bad and some revisions of the K8 core did not support ECC and/or 2GB modules. I would try another CPU with the Asus board. San Diegos are cheap and should support 2GB ECC modules with the Asus board, if more than one fail to do so I would think the issue is the board or the memory.

But I used two Opterons, 170 and a 180 both latest revision! They were meant to support ECC memory and I see the ECC option on ASUS bios.
Unfortunately in both cases the behaviour is the same.
So you suggest to find another ASUS? Can't find another one cheap on Ebay, but I see an Abit AN8 for 25€ plus shipment cost....

Mamba wrote:

But I used two Opterons, 170 and a 180 both latest revision! They were meant to support ECC memory and I see the ECC option on ASUS bios.
Unfortunately in both cases the behaviour is the same.
So you suggest to find another ASUS? Can't find another one cheap on Ebay, but I see an Abit AN8 for 25€ plus shipment cost....

Yes those Opterons are late revisons and should work fine with 2GB sticks, if one stick works so should 4 even if you perhaps have to lower the memory speed to 333 Mhz in some cases and use 2T timing. Your board do supports 2GB modules and ECC but if you have tried different CPUs and know the memory is fine and works together then my next step would be to try another board. I do not know if the Abit board support ECC memory but there are mirrors of the old Abit FTP out there so you should be able to find the manual.

I will try to lower the bus to 333MHz,don't know if I did it anyway.
I can tell that the first time (after several attempts) that the system booted with TWO sticks in single channel, it says DDR333 even if in the bios I left to AUTO all options, including frequency, and those are PC3200R sticks. I Always use 2T timing.

Maybe if I use more of them I have to force to 333MHz? But why? Rank related matter? The sticks are 2Rx4 banks so should be ok to use 4 of them, cause Opterons' memory controller can handle 8...

And why I obtain the same errors even with NON ECC memory?

Mamba wrote:

I will try to lower the bus to 333MHz,don't know if I did it anyway. I can tell that the first time (after several attempts) hta […]
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I will try to lower the bus to 333MHz,don't know if I did it anyway.
I can tell that the first time (after several attempts) htat the system booted with TWO sticks in single channel, it says DDR33 even if in the bios I left to AUTO all options, including frequency, and those are PC3200R sticks. I Always use 2T timing.

Maybe if I use more of them I have to force to 333MHz? But why? Rank related matter? The sticks are 2Rx4 banks so should be ok to use 4 of them, cause Opterons' memory controller can handle 8...

And why I obtain the same errors even with NON ECC memory?

Have you tried to clean the memory slots and have you checked if the board has any broken traces and/or bad caps?

A BIOS update is also worth a try.

1303 is the latest bios and I reflashed it.
I will check for dust or dirt again, as for caps I don't see problems, but maybe I can't recognize a bad one except if it is really damaged or about to explode...

I have an Abit AN8 SLI and Opteron 165. How does one determine ECC support exactly and which ECC 2GB DDR sticks do I need to look for?

swaaye wrote:

I have an Abit AN8 SLI and Opteron 165. How does one determine ECC support exactly and which ECC 2GB DDR sticks do I need to look for?

I can tell that Opterons support 8ranks in total AND ECC memory so you should be able to install any 2Gb stick of ram in a single slot as soon as it's dual rank. There should be written somewhere 2Rx4 or something like that (2Rx?). At least in theory, cause the memory controller is entirely on the CPU.
In real life you can easily see that not all nforce4 boards support these memory.
Abit specs declare that AN8 support 8Gb max of ram, I think that it's all about ECC ram cause I don't remember any manufacturer who sold 2Gb DDR sticks non ECC, but maybe I'm wrong.
Still I'm here to obtain some prove for my speculation, cause I would gladly get rid of my A8N Premium that is making me crazy, and get a AN8.

I got 8GB of ECC DDR PC3200 and have tried it. The system POSTs and I can run Memtest86+ fine with 2x2GB installed. All 4GB is recognized. However, trying to boot XP or a Vista x64 install CD causes the system to power off and this is 100% repeatable. I can't determine what is causing this. I thought perhaps the 32-bit memory remapping, but disabling that did nothing.

There is no ECC enable/disable setting in the AN8-21 BIOS, nor in the last mod BIOS available on the lejabeach site. ECC is not mentioned anywhere in the BIOS nor on the POST screens as far as I can tell.

The Abit AN8-SLI web page mentions 8GB support, but not ECC support.

I got it working. It was RAM timing that was causing the shutdown. I had to set RAS Precharge to 6T.

However, it appears that ECC is disabled.

Getting 4 of these DIMMs going is nigh impossible. I think it might be working at DDR200 speed but it's hard to be positive it's stable.

The power off issue is a parity error being detected I think.

Overall I don't suggest AN8 for 2GB registered PC3200. Socket 939 in general is a pain in the rear when it comes to memory compatibility, especially with 4 DIMMs.

Nice, so ECC Reg. DDR works on non-Asus boards too. 😀
I was wondering - is it possible to use these RAM on socket 754 A64?

Well it sorta works. I wouldn't suggest it. The AN8 board doesn't officially support buffered ECC DIMMs and I would say it shows.