- Update /usr/syno/etc.defaults/scemd.xml file.
DUAL_MODE_HIGH is for the "cool mode" (i.e., when Synology keeps things cooler at the expense of noise) DUAL_MODE_LOW = "quiet mode" I've updated the "low mode" only, like this:
<adt_fan_config skip_check_temp="10" type="DUAL_MODE_LOW" hibernation_speed="UNKNOWN">
<alert_config threshold="2" period="30" alert_temp="95" shutdown_temp="100" name="cpu"/>
<alert_config threshold="2" period="300" alert_temp="58" shutdown_temp="61" name="disk"/>
<alert_config threshold="2" period="30" alert_temp="68" shutdown_temp="71" name="m2"/>
<alert_config threshold="2" period="30" alert_temp="95" shutdown_temp="100" name="nic"/>
<pwm_config name="pwm2" pwm_duty_high="255" pwm_duty_low="80" high_freq="yes" sensor_type="manual"/>
<fan_mapping_config name="internal" pwm="pwm2" order="0"/>
<fan_mapping_config name="internal" pwm="pwm2" order="1"/>
<fan_mapping_config name="internal" pwm="pwm2" order="2"/>
<manual_config name="cpu_temperature" threshold="2" period="30" temp="0" fan_speed="30"/>
<manual_config name="cpu_temperature" threshold="2" period="30" temp="66" fan_speed="100"/>
<manual_config name="cpu_temperature" threshold="2" period="30" temp="76" fan_speed="150"/>
<manual_config name="cpu_temperature" threshold="2" period="30" temp="84" fan_speed="200"/>
<manual_config name="cpu_temperature" threshold="2" period="30" temp="90" fan_speed="255"/>
<manual_config name="disk_temperature" threshold="2" period="300" temp="0" fan_speed="30"/>
<manual_config name="disk_temperature" threshold="2" period="300" temp="47" fan_speed="100"/>
<manual_config name="disk_temperature" threshold="2" period="300" temp="52" fan_speed="150"/>
<manual_config name="disk_temperature" threshold="2" period="300" temp="56" fan_speed="200"/>
<manual_config name="disk_temperature" threshold="2" period="300" temp="58" fan_speed="255"/>
<manual_config name="m2_temperature" threshold="2" period="30" temp="0" fan_speed="30"/>
<manual_config name="m2_temperature" threshold="2" period="30" temp="57" fan_speed="100"/>
<manual_config name="m2_temperature" threshold="2" period="30" temp="62" fan_speed="150"/>
<manual_config name="m2_temperature" threshold="2" period="30" temp="65" fan_speed="200"/>
<manual_config name="m2_temperature" threshold="2" period="30" temp="68" fan_speed="255"/>
<manual_config name="nic_temperature" threshold="2" period="30" temp="0" fan_speed="30"/>
<manual_config name="nic_temperature" threshold="2" period="30" temp="78" fan_speed="150"/>
<manual_config name="nic_temperature" threshold="2" period="30" temp="86" fan_speed="200"/>
<manual_config name="nic_temperature" threshold="2" period="30" temp="92" fan_speed="255"/>
- Restart the scemd service
From the SSH session: systemctl restart scemd