The RN104 only has 512MB RAM (soldered on) and a slow CPU. It's the least powerful model that ever shipped with OS6. The ARM models such as the RN104 don't have the resources to handle those extra features.
The Ultra 4 is the least powerful model that can run the x86 OS6 firmware (though of course unsupported) but it comes with 1GB RAM and you can upgrade it to have more.
If the temperature is above safe levels it would alert you. If you want the system to be more aggressively cooled you can go to System > Performance and choose the Cool profile. You can also do things like set a higher minimum fan speed through SSH if you want to.
FWIW, I always recommend upgrading the RAM in the legacy x86 models to 2 GB (or more) when converting them to OS-6. Shipping x86 OS-6 NAS all have at least 2 TB of RAM.
Also, you'll find there are other services that are disabled on the RN104 - AntiVirus being one. You should disable any services in the RN104 that you don't actually use (or can live without), since they will add to the memory footprint even if they aren't in active use. If you use Plex, then it'd be best to run it on the Ultra, and not the RN104.
in my opinion it is not a question of memory. but simply in ARM architecture. it was not carefully matched and only the critical parameters were left. If only by memory. it's my age. NAS310 displaying all parameters of CPU, RAM, temp. Would also not be displayed and there is only 256MB of RAM
in my opinion it is not a question of memory. but simply in ARM architecture.
Back in 2015, Netgear said the graphs were not provided on the ARM products for performance reasons.
FWIW, memory is a scarce resource on the RN100 series. Netgear had to drop the AV feature on that platform not that long ago, because the system simply was no longer capable of running it.
However, the RN200 series has 2 GB, and it does have enough horsepower to display those graphs. So Netgear simply chose not to implement the feature on the RN200.
