Memory Upgrade and incorrect bios display

[BobNY]

I have a Dell Dimension 8100 series desktop computer. The chipset is an Intel 850. The machine comes with 4 RIMM sockets, slots 1 and 2 each containing a 64MB RDRAM non-ecc Memory module. Slots 3 and 4 are occupied by CRIMM's.

I decided to upgrad memory and purchased (2) 256MB Rambus R800 RDRAM memory modules. According to Intel specs, the memory modules should be compatable with the system.

I went ahead a removed the CRIMM's from slots 3 and 4 and placed the 256MB modules in these slots. The result was error messages, a need to enter the bios, and an indication in the bios that the modules were ECC rather than non-ecc. The machine through repeated bootings, memory dumps, and other diagnostic routines would finally complete booting and would operate.

I decided to remove all the modules and install only the 256 modules in slots 1 and 3; the crimms were reinstalled in 3 and 4. The machine ran fine with no error messages or unnecessary routines. BUT, the bios still identified the 256MB modules as being ECC rather than non-ecc.

I then removed the CRIMMS from 3 and 4 and installed the 64 MB chips in these slots. The machine booted up without any problems. But, again, the bios indicated that the 256MB modules were ECC. The 64 MB modules were correctly identified and the total memory was correctly identified as 640MB.

My questions are:
1) Why are the 256MB modules being incorrectly identified?
2) If the 256MB modules are identified as ECC while the 64MB modules are identified as non-ecc, will this eventually create problems? The reason I ask is that the supplier of the modules has allowed me to keep the modules for a trial period before I return them if necessary. But, they have no opinion regarding the phenomena described above.

Anyone out there have an opinion on this?

Thanks in advance,
Bob

 

[BChumie]

Hello Bob,

Just cause the memory RIMMS are being identified as being ECC doesn't mean they are running in ECC mode. You might have purchased the ECC memory by mistake and not realized that is what you were getting. Just make sure ECC is disabled in the BIOS so that the 64 meg RIMMS are not effected by the side effects of having ECC turned on without having the capablity to support it.

It is my opinion that as long as you have ECC disabled in the BIOS then you should not have any new problem with how they are being identified.

ALSO you might want to go to Dell's website and download a BIOS update. That way you can see if it is a BIOS issue that is causing this to be identified incorrectly.

Brad

 

[BobNY]

BChumie,
Thanks for your response. I believe that the modules are true Non-ecc parts. The part number corresponds to a non-ecc component, and the physical characterisitics of the module are consistent with a non-ecc vs an ecc module. So, the module is likely to be a non-ecc module.

The bios cannot be changed because the machine is utilizing a proprietary bios manufactured by Promise technologies, the manufacturer of an AT 100 PCI controller card that is interfaced with a Trios multi-disc drive switch. I tried to go into the bios to change the feature from 'ECC' to "non-ecc". But, the option is not available. The bios does not permit one to change these options. So, the only positive conclusion I can draw from this is that perhaps the Bios is mis-identifying the modules. But, this mis-identification is not adversely effecting the operation of the machine. Is this possible?

 

[BobNY]

There is a new twist to this problem. VERY intermittently, the machine will not boot up unless the bios is entered. But, nothing needs to be done. Just enter the bios, go into physical memory and then exit the bios with no changes made. Then windows boots up. But, if a message reads that memory has changed and one does not go into the bios, the machine will not boot to windows. This problem occurs perhaps once out of 50 startups. What's this all about?