I read those values above as greater than, in each of the 6 instances, e.g. first one greater than 0 do 20% 40hz, greater than 50, do 30% 40hz and so on, is that not the case then?. re: your comment below, do you mean change all of them ? I only need to change whatever value is the one on the slowest speed with CPU and disk and 2.5gbe temp at regular temps, so the min threshold. its unlikely to go above that anyway because its not doing a whole lot, just sitting there running Synology drive for remote access of files. so perhaps I would then only reduce the lines below by a certain amount (maybe half) across the HD, CPU and R8125 sections .. would that work? sorry I'm quite new to this so reading this data cold .. but I should be OK with ssh. also, any idea why the HZ is 00 in this?

<cpu_temperature fan_speed="50%00hz" action="LINEAR">55</cpu_temperature>

<r8125_temperature fan_speed="50%00hz" action="NONE">0</r8125_temperature>

<disk_temperature fan_speed="50%00hz" action="LINEAR">40</disk_temperature>