Fluctuating NB frequency - CPU or Motherboard

[andre_888]

In CPU-Z the Memory tab is showing that the NB frequency occasionally dips when idle, and stays down when under load. It is causing start stop action in games as my GPU accesses system memory. The NB frequency drops to 1400MHz from 1800MHz.

Is this a problem with the CPU or the motherboard? Neither manufacturer can pinpoint the problem.

I believe I can get an RMA with either manufacturer, but it will cost a lot in shipping, feel like a lot of work, and it would be upsetting if the wrong component ends up being sent for replacement.

 

[firo40]

That is a motherboard issue most likely, thats not normal for a nb to stay idle under load

 

[andre_888]

Thanks Firo40.

MSI - the motherboard manufacturer never replied to my tech support request when I asked for diagnostic tools to identify the problem. AMD`s RMA procedure was really quick. I received the replacement CPU to only discover the problem is still there.

Unfortunately, the problem was indeed with the motherboard.
After wasting 17$ for tracked shipping of the CPU for the RMA, I am in no mood to take everything apart... I should nonetheless. Solving the problem is part of the fun.

 

[andre_888]

I installed Windows 7. Since the NB frequency has been stable.

Power management in Windows 8 doesn't have anything about the Northbridge or the memory controller.

I guess the problem really hasn't been solved, but at least I know how I can avoid it. Well, until I get locked out of the Windows 7 installation.