MSI B760M Mortar Noisy AIO Solution

MSI B760M Mortar Noisy AIO Solution | Generated by AI

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Question: Why is my MSI MAG B760M Mortar + Thermalright Frozen Prism 240 AIO fan so loud?

Answer:

Your motherboard is probably not the noisy part. The usual causes are:

AIO pump/fan curve is too aggressive

The Thermalright Frozen Prism 240 uses:

2 × 120mm PWM radiator fans
up to ~1850 RPM
AIO pump

At default BIOS settings, many boards run CPU cooling fans based on CPU temperature spikes. Modern Intel CPUs (especially i9-13900KF on B760M) have very fast temperature jumps:

idle:
CPU 35-45°C

open browser/build code:
CPU spike → 70-90°C in milliseconds

BIOS sees spike:
fan jumps 1000 → 1800 RPM

Result: annoying “jet engine” behavior.

i9-13900KF is a very hot CPU

Your setup:

CPU: i9-13900KF
Board: MSI MAG B760M Mortar
Cooler: Thermalright Frozen Prism 240

The 13900KF can easily hit:

PL2 power:
~250W+

Cinebench:
90-100°C possible

A 240mm AIO is borderline for this CPU.

The cooler can handle gaming/workloads, but heavy all-core loads will make fans ramp.

MSI default BIOS fan mode

MSI often ships with:

CPU Fan:
Smart Fan Mode ON

Temperature source:
CPU

Curve:
aggressive

Try:

BIOS:

Hardware Monitor
    CPU Fan:
        PWM mode

    Fan curve:
        30°C -> 20%
        50°C -> 40%
        70°C -> 70%
        85°C -> 100%

Do not let it instantly jump to 100%.

AIO pump connected incorrectly

Check cables.

Typical:

Pump power:
AIO_PUMP header

Radiator fans:
CPU_FAN header

ARGB:
JRAINBOW header

If pump is connected to CPU_FAN and controlled badly:

pump speed changes
↓
water flow changes
↓
temperature oscillation
↓
fan noise

Better:

AIO_PUMP = 100% fixed
CPU_FAN = temperature controlled

13900KF motherboard power limits

B760 boards often allow unlimited Intel turbo:

PL1 = 253W
PL2 = 253W
Tau = unlimited

For a quieter machine:

BIOS:

CPU Lite Load:
Mode 5-7

or

Long Duration Power Limit:
125-200W

Performance loss is small, noise reduction is large.

Example:

Cinebench R23:

253W:
40000 pts
100°C
loud

180W:
36000-38000 pts
80-90°C
much quieter

Check whether the noise is actually the pump

AIO noises:

Fan noise

whoosh / air noise
changes with RPM

Fix:

lower fan curve
replace fans

Pump noise

buzzing
rattling
water sound
constant

Fix:

set pump to fixed 100%
check mounting orientation
remove air bubbles

For your exact hardware, I would do:

1. BIOS:
   AIO_PUMP = 100%

2. CPU fan curve:
   40% until 60°C
   70% at 80°C

3. Enable Intel power limits:
   PL1/PL2 = 200W

4. Undervolt:
   CPU Lite Load Mode 5-7

5. Use MSI Center only for monitoring, not fan control

A 13900KF + 240mm AIO can be quiet, but not with unlimited turbo + aggressive fan curves. The B760M Mortar is actually a good board; the noise is mostly the combination of 13900KF power behavior + 240mm radiator + default curves.

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