RAM-NB Issues. Can't my NB handle my ram?

Mar 17, 2018
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Hey folks!

I'm currently oc-ing my old desktop-pc and I ran into an issue I can't explain. I hope you can help me understand.

So I'm trying to get my ddr3 ram to 2400MHz, which it is qualified for. I'm doing this by setting the ram frequency in BIOS to 1866MHz, since it is the highest applicated frequency and then work my way up with the system clock. No worries: I've got all other frequencies under control and keep them steady to where they were. Also, I already confirmed that my systemclock can go beyond 150MHz, but I only need it to reach 127MHz.

Everytime I go past 2200MHz of ram frequency, my system fails to POST. There are two different errors that occure related to this:

If I raise the NB frequency to above 1050MHz, the screen stays black and BIOS does not give any beep code at all. Not even the single beep which notifies of a succesful POST.

If I lower the NB frequency below a certain point - even if I don't raise my ram frequency - I get a "Base 64 K RAM failure". This normally indicates bad ram. But if I revert my settings, everything is fine again. The point, where this happens seems to be relative to the current ram freq.

At one point my system even booted with 2400MHz RAM freq! No problems, until I shut it down and it failed to POST again.

The question is: How do NB frequency and RAM frequency relate? Is a certain frequency-ratio compulsory for stable operation?


My System:
A8-3870k APU
2x4GB Kingston HyperX Predator qualified for 2400MHz 11-13-13-30-54
MSI A75MA-G55 Motherboard
ASUS 6670HD Graphics card
SilentMAXX fanless II 500W PSU
 
are you adding voltage to the ram when you raise the freq? your not saying you are raising the voltage to the ram so im not sure if your trying to do it on not.....you have to raise the ram voltage to 1.65volts if im looking at the correct part online...you would need to post the ram part # for us to know the voltage spec if you dont know it
 
Mar 17, 2018
2
0
10
No, the voltage is set to 1,65V, as specified in the XMP and Datasheet. I'm just wondering if the issue could be Northbridge related.. If it indicates that something is broken or if it is normal behaviour.

I also ran memtest86 on both ram modules and on three different ram-slots. No errors were found.