Running Two DDR400 1GB Sticks Reduces DRAM Freq to 100Mhz

[Laztlain]

Hi,

I have a strange issue that I am hoping I could get some help with....

I currently have the following setup:
Asus A8R32-MVP Deluxe 0701 BIOS
Opteron 170
Sapphire Vapor-X 4890 1GB
OCZ 550w PSU
4x512mb Kingston HyperX PC3200 DDR

I just got a hold of 2 1GB sticks of OCZ Platinum PC3200 and tried to replace 2 of my 512mb sticks with these.... and thats when things went downhill!

This issue is that as soon as BOTH of the 1GB sticks are installed together they immediately set the DRAM Frequency to 100MHz regardless of the setting in the BIOS. I have removed all of the 512mb sticks to perform some tests. When either of the 1GB OCZ sticks are installed alone in the mobo they read 200MHz in CPU-Z just fine. However, as soon as I install the second 1GB stick, whether single channel or dual channel, the system will ALWAYS use a DRAM Frequency of 100MHz. I have tried adjusting timings in the BIOS but nothing seems to help. Also, if I try enabling a higher MEMCLK Frequency than 100 MHz in a program like A64 tweaker the system will immediately shut down.

Im not sure if this is an issue with the OCZ Platinum brand and the A8R32-MVP Deluxe motherboard or if all 1GB memory modules will cause this issue?

If it helps, both of the OCZ modules have the P/N OCZ4002048ELDCPE-K on them. However CPU-Z identifies only one of the modules with this part number and the other with OCZ4001024ELPE.

Any help is appreciated!

 

[Emulex]

you could help by explaining the rank.

rank used to be simple like "double-sided" but now you can have single sided boards with quad-rank memory.

the number of slots is not the limit - it is the rank or density of chips (or lack thereof).

the motherboard just can't drive that much

 

[Laztlain]

The mobo manual does metion "when you install four double-sided 400 MHz DDR DIMMS the frequency of each module downgrades to 333 MHz." However, I do not believe this is the issue since the 1GB modules are downgrading to 200 MHz when only 2 are installed.
Each of the modules are double sided low density. But somehow I have the feeling I have not answered your question....