CPU cooler scaling is wrong in bios, values provided (MSI A520M-A PRO)

[akimismo]

Hello,
I share with you a support ticket I just opened with MSI. I was wondering if you encountered this problem and found the cause? 

I recently purchased a msi a520m-a pro mainboard. It came with the latest bios 7C96v1I and I never updated it. I use an amd ryzen 5 5500 with the stock cooler, an amd wraith stealth, ranging from 600 to 1900 rpm.
When I want to set a fan curve for the cpu cooler in the bios, the following rpms are given with the following rpm percentages:

0% = 620 RPM

10% = 785 RPM (165 RPM above 620 = ~12% of 1340 span).

20% = 950 RPM (330 RPM above 620 = ~25% of span).

30% = 1100 RPM (480 RPM above 620 = ~36% of span).

40% = 1275 RPM (655 RPM above 620 = ~49% of span).

50% = 1445 RPM (825 RPM above 620 = ~62% of span).

60% = 1640 RPM (1020 RPM above 620 = ~76% of span).

70% = 1830 RPM (1210 RPM above 620 = ~90% of span).

75% = 1960 RPM (1340 RPM above 620 = 100% of span).

75% to 100% = 1960 RPM (1340 RPM above 620 = 100% of span).

Obviously the problem here is, that at 75% rpm speed set in the bios, the fan reaches its full potential of around 1900rpm an remains at that speed between 75% and 100% setting, and subsequently all % settings give wrong rpms.

Please advice

Regards

[Landvader07]

1 hour ago, akimismo said:

Hello,
I share with you a support ticket I just opened with MSI. I was wondering if you encountered this problem and found the cause? 

I recently purchased a msi a520m-a pro mainboard. It came with the latest bios 7C96v1I and I never updated it. I use an amd ryzen 5 5500 with the stock cooler, an amd wraith stealth, ranging from 600 to 1900 rpm.
When I want to set a fan curve for the cpu cooler in the bios, the following rpms are given with the following rpm percentages:

0% = 620 RPM

10% = 785 RPM (165 RPM above 620 = ~12% of 1340 span).

20% = 950 RPM (330 RPM above 620 = ~25% of span).

30% = 1100 RPM (480 RPM above 620 = ~36% of span).

40% = 1275 RPM (655 RPM above 620 = ~49% of span).

50% = 1445 RPM (825 RPM above 620 = ~62% of span).

60% = 1640 RPM (1020 RPM above 620 = ~76% of span).

70% = 1830 RPM (1210 RPM above 620 = ~90% of span).

75% = 1960 RPM (1340 RPM above 620 = 100% of span).

75% to 100% = 1960 RPM (1340 RPM above 620 = 100% of span).

Obviously the problem here is, that at 75% rpm speed set in the bios, the fan reaches its full potential of around 1900rpm an remains at that speed between 75% and 100% setting, and subsequently all % settings give wrong rpms.

Please advice

Regards

Can you set your own fan curve? 

[NorKris]

how many fans have you tested with on the header?

[akimismo]

7 hours ago, Landvader07 said:

Can you set your own fan curve? 

Yes, that's how I realized the problem

[akimismo]

1 hour ago, NorKris said:

how many fans have you tested with on the header?

Unfortunately I only have this one brand new amd wraith stealth. rpms work fine from 600 to 1900, just not at the correct bios %

[NorKris]

9 minutes ago, akimismo said:

Unfortunately I only have this one brand new amd wraith stealth. rpms work fine from 600 to 1900, just not at the correct bios %

ok. other case fans  can be tested on the header  to see if its the motherboard PWM controller  trolling you  or somthing inside the  wraith stealth

[freeagent]

Asus has Q-fan, software in UEFI that sets itself up to your fans. If MSI has an equivalent I would run it.

[akimismo]

29 minutes ago, freeagent said:

Asus has Q-fan, software in UEFI that sets itself up to your fans. If MSI has an equivalent I would run it.

When using MSI's cooling wizard from the MSI Center it gives me the same values as in the bios. See pictures.

 

[akimismo]

I found an older topic by @YobB1n with the same problem (did you find a solution by any chance?). Also MSI mainboard. 

 

[akimismo]

I wanted to also check the sys_fan and found out the following:
- cpu fan pwm goes from 0% - 75%, hitting full speed at 75%
- sys fan pwm goes from 20% - 100%, keeping lowest speed between 0 - 20%
As both fans are new I would exclude a misfunctioning here, particularly because I found similar forum topics. At least now by recalculating the real scaling my fan curve works.

 

Not sure if it's the MSI board giving wrong values or the fans having built in "safety" limits