Memory power management

[VMHB]

While running kernel 3.16.7-29 on an AMD based machine the clock speed is 
being changed on the DDR3 modules. This is causing issues with our debugging 
tools which rely on the clock.

As far as I know this should only be changed following a POWER DOWN or SELF 
REFRESH sequence. This only seems to happen when Linux is booted and not under 
the BIOS. 

I have searched in the kernel code and on the internet and although there is 
information and patches regarding power saving modes I cannot find any code in 
the kernel I am using.

Can someone please give me any information on the source of this and 
preferably how it can be stopped?

I am not subscribed to the list and would like to be copied personally with 
any responses.