PC Processors

[jiatistuta]

Hello Folks,

I have Ryzen 2600x and Asus Prime B350M-A/CSM Mobo in my rig. Recently I notice the BCLK is always 99.8 MHz instead of 100 MHz. After some research, it turns out to be the spread spectrum configuration issue. The motherboard has been updated with the latest Agesa 1.0.0.3ABBA BIOS (Version 5220). I went through the BIOS config menus but there was no entry for spread spectrum. How can I disable this function? Is there a way to mod the BIOS or the BIOS config CMO file? Actually I tried to decode the CMO file with a hex file reader but I don't understand which line relates to spread spectrum, or whether it exists at all.

Thanks! 

[elstaci]

I wouldn't mess with modifying the BIOS.  I would suggest to ask Asus Support to give you a BETA BIOS to download instead. That way the warranty on your motherboard won't be voided.

This User has the same exact issue as you do with the Clock @ 99.8 in a Asus Motherboard. He also couldn't find any BIOS settings: ROG STRIX B350-F GAMING, Where is VRM Spread Spectrum option? [Archive] - ASUS Republic of Gamers [R... 

I went to Asus Support and started a "Live Chat" with them concerning your question. I also have a Asus Motherboard so I have an account with them even though you don't need one to chat with them.

The Tech needed the Serial Number of your motherboard so I highly suggest you start a "Live Chat" and the Tech Support says it is best if your Contact them directly.

Here is a copy of the Chat I had with Asus Tech Support:

Hello!

Please give me a moment while I review your inquiry.

Hi Exxxx, thank you for contacting ASUS, my name is Monique H.

Hi Monique

I understand that you are having issue with BIOS settings.

yes.I am a long time Asus customer and I am active at AMD Forums.

This User with the motherboard I mentioned is asking this question:

I have Ryzen 2600x and Asus Prime B350M-A/CSM Mobo in my rig. Recently I notice the BCLK is always 99.8 MHz instead of 100 MHz. After some research, it turns out to be the spread spectrum configuration issue. The motherboard has been updated with the latest Agesa 1.0.0.3ABBA BIOS (Version 5220). I went through the BIOS config menus but there was no entry for spread spectrum. How can I disable this function?

can you help me or give some suggestion that I can relay back to the Asus User at AMD Forum?

Thank you for that information Exxxx, we at ASUS are very happy to have you as a customer.

I will do my best to assist with this issue.

Thanks, This will be useful for me as well as a future reference.

Just a moment please.

I downloaded the User Asus Manual but under BIOS there are no explanations for the various BIOS Settings as in other Asus Manuals.

I am still with you, just a moment please.

No problem. I realize this is an unusual BIOS Setting. I found another thread where another Asus User was having the exact same issue on another Asus motherboard and he couldn't find the BIOS setting for Spread Spectrum.

This is the Non-AMD thread I found: ROG STRIX B350-F GAMING, Where is VRM Spread Spectrum option? [Archive] - ASUS Republic of Gamers [ROG] | The Choice of…

Just to confirm your CPU is Ryzen 5 2600X correct?

Yes that is the User's Processor.

Is the BIOS updated?

Yes he said he has the latest version 5220

Thank you for that information.

Can you provide me the the serial number?

of what? the motherboard or cpu

For the motherboard.

No, Would it be better if the User contacts you directly using "Live Chat"?

Yes that would help.

I will make a copy of this chat and post it on his thread.

Okay , I will let him know that is the best thing to do.

But will you be able to assist him in this matter if he does contact Asus Chat?

I would like to escalate his case to provide further support with this issue.

fantastic I will let him know so that he will contact you as soon as possible.

Thanks you very much in your assistance

Good day!

[jiatistuta]

Elstaci, 

Thank you so much! I will contack Asus and update my post ASAP.

[jiatistuta]

I have contacted Asus, and this case has been escalated to the technical team. They will response in 48 hours.

[elstaci]

Asus Support contacted me via email and showed me how to disable Spread Spectrum in your BIOS:

My name is Akime F. from ASUS Escalation Support. I hope you are having a good day.

I understand that you wanted to know how to disable spread spectrum. 
 
I am extremely sorry to hear that you are experiencing this issue. I would be more than happy to assist.
 
Our Engineering team has indicated in order to disable spread spectrum, please disable it in BIOS.

Go to BIOS -> AI Tweaker -> SB Clock Spread Spectrum -> Disabled

F10 to save

I was pleasantly surprised that Asus Support contacted me to let me know how to disable Spread Spectrum in BIOS. I wasn't expecting that.

So Kudos to Asus Support. 

NOTE: You probably will get the same info as I did soon if not already by Asus Support.

[jiatistuta]

Hi elstaci,

Thank you again for your kind help. This is what Asus replied me:

Spread Spectrum can be found as the below path in BIOS

AI Tweaker-->DIGI + VRM-->VRM Spread Spectrum

Tips: Spread Spectrum can be selected Enable or Disable only when another selection, VDDCR CPU Switching Frequency, is set as "Auto mode"

I tried but VDDCR CPU switching Frequency can't be set to AUTO. It only allows me to enter 200, 250, 300, or 350. There is no option for VRM spread spectrum. There is no option of SB clock Spread Spectrum either. I will keep in touch with Asus tech team.

[black_zion]

Those options are in ASUS AI Suite, specifically Dual Intelligent Processors 5 --> Digi Plus Power Control, but it is perfectly normal behavior for all Socket AM4 processors to not run at a perfect 100mhz, fluctuating between 99-101mhz, though newer AGESA revisions have tightened it up significantly to +/- 0.3mhz.

[shinkojiro]

That isnt the same spread spectrum to be disabled.

[shinkojiro]

Thats not the same spread spectrum you want to disable to make BCLK set to 100, that one is for the VRM. For ASUS boards its in Extreme/AI Tweaker Tab -> Tweaker's Paradise -> Very top option being 'SB Clock Spread Spectrum. Set that to disabled.

This may look different from the B450 board.

Another option is to change the BCLK from 100 to Auto. For some people, including myself, that also does the trick.

[jiatistuta]

Thank you very much for the reply. I found that my B350 Mobo does not have this feature at all. So I will just live with it. 

[shinkojiro]

You'll probably be better off asking at Overclock.net for Motherboard related bios questions next time. AMD doesn't deal with where or how they place their bios options.

[dorx86]

Has anyone figured this out? I have the same motherboard and issue.

[jiatistuta]

The Asus tech support team replied me as follows:

1. BIOS update to 5220 (again)
   1. If works, go to BIOS -> Exit -> Load As Default
2. If step 1 fails, please swap CPU and test
   1. If it passes, case close
3. If step 2 fails, please exchange motherboard 

Obviously, this is not something that relates to the mobo functions. I believe the prime B350 is by the low end therefore it lacks the feature of altering BCLK. I didn't bother swapping CPU or exchanging the board. Everything is just fine. 

[dorx86]

yeah i think it is locked for us. If anything you would have to mod the bios to be able to enable or disable spread spectrum.

[dorx86]

I actually did some digging in the bios file from overclockers.net, they have a program which u can enable or disable features that are locked. And Spread Spectrum does indeed seem to be on but hidden for some reason.

[jiatistuta]

Got you. You may just focus on using the rig instead of tweaking these minor parameters. Easy life happy life. 

[dorx86]

Oh yeah I’ve been using the rig for a while. It’s just annoying to see 3.492 ghz instead of 3.5 lol. Modding  the bios will also give the full AMD CBS options which are also also hidden.