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Ryzen motherboard clock generator

Scougar

Scougar

Scougar

Soldato
Joined
30 Jan 2007
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Is anyone able to explain how the clock generators work on some of motherboards did the memory? Does this has a negative impact on performance?

I.e. If I have one system running with the clock gen at 3200 memory, and another with the clock gen at 3200 memory, is the clock gen causing infinity fabric to be lower clocked internally or something?

I.e. is the use of the clock gen actually not improving performance as much as it should due to running externally, and not using it (if the same memory speed could be achieved) result in better performance?
 
The dficlk is linked to the memory at a 1:2 ratio.
So using the external clock generator will have the effect of increasing the memory speed, which in turn will raise tge dficlk and gain performance from both the higher memory speed and df.

In a way it's like htref clocking on AM2/3 where increasing ht ref would increase the cpu-nb and the ht link and the memory frequency.
 
But does it increase like it would without the black generator? To me this seems like a ratio thing, so something has to be running slower.
 
whatever the memory speed is, the df will run at half memory speed.

Example ddr 2400 memory and df will be 1200.

If you have a 2400 memory and increase the clock gen by 10mhz then say it overclocked ram to 2560 then the dfclk would be 1280.
 
The way I have read it is that it is coupled to the memory bus so that you can adjust the clock say 125MHz reduce the fsb:mem ratio to say 2400MHz DDR so that the memory is actually at 3000Mhz.

I will have to play around with this at the weekend to make sense of it. If it is actually useful?

I also understand that PCIe Gen 3 is disabled and only Gen 2 is available. This may affect high speed NVMe access speeds.
 
nkata said:
The way I have read it is that it is coupled to the memory bus so that you can adjust the clock say 125MHz reduce the fsb:mem ratio to say 2400MHz DDR so that the memory is actually at 3000Mhz.

I will have to play around with this at the weekend to make sense of it. If it is actually useful?

I also understand that PCIe Gen 3 is disabled and only Gen 2 is available. This may affect high speed NVMe access speeds.
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That would be super useful. It feels like people are blindly using it without really understanding how it works, and if it has impact elsewhere. (like possibly going down to Gen 2 on PCI-E... that was a total surprise!)

Useful little snippet here: https://www.reddit.com/r/Amd/commen...nt_world_1_overclocker_just_posted_a/depd4v7/
 
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it works exactly the same as base clock on old amd cpu's, apart from you north bright, ht link are in the cpu, its not rocket science :p the reason why its better to do base vs multi with ryzen atm is because you can run the 2400mhz ram sub timingswhile the ram is running at 3200, so the timings for 3200mhz are way tighter than if you run the ram speed at 3200mhz.
 
Jumper118 said:
it works exactly the same as base clock on old amd cpu's, apart from you north bright, ht link are in the cpu, its not rocket science :p the reason why its better to do base vs multi with ryzen atm is because you can run the 2400mhz ram sub timingswhile the ram is running at 3200, so the timings for 3200mhz are way tighter than if you run the ram speed at 3200mhz.
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I don't know what's so hard to understand about this either. I explained numerous times that Df is half the operational speed of memory clock.
 
I just want to ensure I understand it fully.

A lot of the time, this place is very light on technical information and high on BS and claims without anything to back it up. Was hoping for more than just your word, and some technical discussion.
 
Scougar said:
I just want to ensure I understand it fully.

A lot of the time, this place is very light on technical information and high on BS and claims without anything to back it up. Was hoping for more than just your word, and some technical discussion.
Click to expand...

Sorry dave my bad you were correct.
Jees
 
Scougar said:
:p
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:p i have to admit i didn't make it clear because i failed to acknowledge you were comparing one cpu with a 3ghz mem setting, vs a cpu using a clock gen to get 3ghz mem frequency.

You then asked if the fabric would change,.i said yes and technically that was wrong of me. I should have said no the fabric would be the same still.
So my bad sorry.
 
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