Where is my added RAM or What in the world is Registered RAM? 1

[Guru2B]

Hi,

I have an AOpen AX6BC motherboard with two 64 meg RAM sticks. I added 256 meg more, now I have 256. I removed all the RAM and tried only the new 256 meg one, the system recognized only 128 of it.

From AOpen's website, I have noticed that they mention Registered RAM. What is this? How do I know if the chip I bought is registered? Will this cause the problem?

Thanks,
Dave

 

[Pete45]

Acording to the Aopen web site your AX6BC mainboard will not take Dimms larger than 128MB. And will only take unbuffered SDRAM.

Registered modules contain a register that delays all information transferred to the module by one clock cycle. Like buffered modules, registered modules are typically used only in servers and other mission-critical systems where it is extremely important that the data is properly handled.

Unbuffered modules are the most common. In unbuffered memory, the chipset controller deals directly with the memory. There is nothing between the chipset and the memory as they communicate. Buffered modules contain a buffer to help the chipset cope with the large electrical load required when the system has a lot of memory. Registered modules are unbuffered modules that contain a register that delays all information transferred to the module by one clock cycle. Buffered and registered modules are typically used only in servers and other mission-critical systems where it is extremely important that the data is properly handled.

You can differentiate between buffered and non-buffered Dimms by the location of the notch on the bottom.

 

[Guru2B]

So...the manual says that I can get up to 768 megs, is it a misprint? What do I have to do to get that capacity?

Dave

 

[Pete45]

Please forgive me Dave I downloaded the manual for the AX6B instead of the AX6BC. I apologize for my mistake.

Upon review of specs for the AX6BC which is what was stated.
You can only obtain 768MB max. by using registered SDRAM.
And it was interesting to note that mixing SDRAM with registered SDRAM is not allowed.

My point is that the stick of 256MB of SDRAM apparently is not registered SDRAM. And further, I don't think the 2 sticks of 128MB SDRAM could be registered SDRAM either. As they would not be compatible at all. It would probably either not boot at all or only boot recognising the 2-128MB(256MB) sticks or the 1-256MB(128MB) only.

A while back I bought a stick of PC133 128MB SDRAM(El cheapo).When I installed it, my machine only recognized 64MB. Later I found it would work properly in another machine that had a different chipset than mine (i440BX). That SDRAM was not compatible with my BE6.

The moral of the my story is this: from here on out I will only purchase my memory from web sites that have a configurator on site to check for compatability. The last several times I've used Crucial.com and haven't got burned.

 

[Guru2B]

Thank you very much for the help.

Dave

 

[marchristensen]

Thanks for the tip on Crucial.com. Prices are great andI will be ordering from them (free delivery until Sept 10).