Question DRAM frequency running slightly lower than DOCP OC

Destim

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Jun 24, 2015
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It's difficult for me to judge whether this behavior is normal.
Windows & BIOS is telling me my ram is running at 3600 (double data rate)
CPU-Z however, shows my DRAM frequency (data rate) running at around 1750-1790 MHz.

I would expect this to run more closely to 1800MHz? (And i think it also did a while ago)
What does this exactly mean? Can i trust this reading?

Is there something wrong in my BIOS settings? (my DOCP settings are on auto)
Is my ram/cpu degrading?

My system is running fine so far, but imho this doesn't look normal.
I am on the latest BIOS version for my motherboard & also latest chipset.
My ram is configured in 'quad' channel 4x8gb
Some screenshots:

 
Last edited:

Kona45primo

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Jan 16, 2021
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Last edited:
It's difficult for me to judge whether this behavior is normal.
Windows & BIOS is telling me my ram is running at 3600 (double data rate)
CPU-Z however, shows my DRAM frequency (data rate) running at around 1750-1790 MHz.

I would expect this to run more closely to 1800MHz? (And i think it also did a while ago)
What does this exactly mean? Can i trust this reading?

Is there something wrong in my BIOS settings? (my DOCP settings are on auto)
Is my ram/cpu degrading?

My system is running fine so far, but imho this doesn't look normal.
I am on the latest BIOS version for my motherboard & also latest chipset.
My ram is configured in 'quad' channel 4x8gb
Some screenshots:

look on the CPU page, bus clock in your case is below 100MHz, some mainboard lets you to change bus clock, but ultimately its decided by your CPU, inside your CPU there is a crystal which resonates at ~100MHz frequency, if yours runs lets say 98mhz then everything connected to your CPU runs at 98mhz * device multiplier
xh1XSpU.png

here in my case its 99.98MHz which is pretty close to 100MHz
vLem7eh.png



bus clock is used by every device connected to your cpu...gpu, nvme etc +-2% performance difference isnt really big deal
 
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Destim

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Jun 24, 2015
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Aha, thanks for the clarifications guys.
My bus speed is indeed hopping around 98.29 - 99.15 MHz

Ram is also running at 1.35v.
I remember my bus speed being at 99,98Mhz or something really close to 100Mhz..
Is this something i could 'fix'..?


EDIT:
I just stumbled upon this page by chance.
Disabling SVM mode did indeed increase my bus speed like it was before.
Interesting...

 
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Aha, thanks for the clarifications guys.
My bus speed is indeed hopping around 98.29 - 99.15 MHz

Ram is also running at 1.35v.
I remember my bus speed being at 99,98Mhz or something really close to 100Mhz..
Is this something i could 'fix'..?
look in bios settings if your bus clock (fsb) can be changed, amd allows some mild bus clock change on ryzens without external clock generator, but not every mainboards offers such setting (even if agesa V2 has it there) and for example nvme drives does not like bus overclock at all, mine samsung 970 crashing just at 101.1mhz xD
 

Destim

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Jun 24, 2015
129
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look in bios settings if your bus clock (fsb) can be changed, amd allows some mild bus clock change on ryzens without external clock generator, but not every mainboards offers such setting (even if agesa V2 has it there) and for example nvme drives does not like bus overclock at all, mine samsung 970 crashing just at 101.1mhz xD
That's good to know. Thanks!