I'm running the nettop PC based on DN2800MT (NM10 chipset), 4GB RAM (DDR3 1066MHz natively), none overclocked. OS is Ubuntu 12.04.
500GB SATAII 3,5" harddrive, miniPCI-e Wifi card, that's all.
After a few minutes the NM10 gets literally hot, I cannot touch it. It does not matter it has the onboard GPU turned on or off. Yesterday I upgraded BIOS to 0155, still the same. Interestingly, this chip does not have any radiator to discharge the heat faster.
It is normal that the Intel(R) NM10 express chipset runs at high temperatures, this processor is designed to operate up to 115°C and you can confirm this on the Technical Product Specification for the motherboard found at the following web site: