first ryzen build, BUS speed jumping around

[MassiveJim]

I have bought an MSI B450M PRO-VDH V2

Set my multiplier in the bios and currently running PRIME95 to test stability, but the BUS Speed is jumping around anywhere from 95mhz to 99ish Mhz, meaning that the overall clock speed is varying by up to 200Mhz.

Spread spectrum is disabled, anything else I should be looking at ?

with the stock cooler temps were up around 59oC
with an old Corsair 120mm AIO I had lying around temps are currently sitting at around 45oC

 

[Meddling-Monk]

Dunno if it's related, as I've only got recent Intel systems, so I don't know if it still applies and to AMD systems (I would assume so though). But if you have Windows Hyper V activated, it causes the Bus speed to appear to change around, but doesn't really. That might be what you're experiencing.

 

[Danny75]

Cinebench R15 will work all cores at 100% but will be more lenient on the VRMs. Could have a look to see if the bus speed fluctuates with that as well.

Maybe aim a fan on the VRMs while Prime is running see if there's a difference.

Could just be a faulty board, or dodgy BIOS though.

What CPU is it? And what happens when you don't set a multiplier and just use PBO/XFR or Game Boost (if that Bios has Game Boost)?

 

[MassiveJim]

CPU is a Ryzen 2600

I have updated to the latest BIOS and that allows you to set the FClck
I set it at 100Mhz and the fluctuation whilst still there has decreased.

as soon as I exit Prime, the Bus speed locks at 100Mhz for a few seconds until the computer clocks the CPU right back down
ill see what cinebench does tomorrow.
ill also try XFR with no overclock.

It is a budget board at the end of the day so if the VRMs aren't up to the job, would it cause this ?

 

[Danny75]

CPU is a Ryzen 2600

I have updated to the latest BIOS and that allows you to set the FClck
I set it at 100Mhz and the fluctuation whilst still there has decreased.

as soon as I exit Prime, the Bus speed locks at 100Mhz for a few seconds until the computer clocks the CPU right back down
ill see what cinebench does tomorrow.
ill also try XFR with no overclock.

It is a budget board at the end of the day so if the VRMs aren't up to the job, would it cause this ?

I'm not sure, just something I'd try. I don't know if some motherboards could be set up so that the bus clock climbs down rather than the CPU speed, when VRMs get too hot. Or if it's just a buggy board that way, or other reason.

 

[an0nym0us]

Not heard of this problem before. Have you tried emailing MSI?

 

[MassiveJim]

Cinebench has it pretty much locked at 99.48 mhz, it moves a little bit but no more than .2 mhz