The memory layout for windows is going to be different than it is under linux. A bad module could still be causing chaos but it might only really be affecting the RDP server rather than firefox.

For CPU, can depend on how you are configured. If you haven't gone through the work of getting your power usage settings under control, linux likes to run the CPU clock frequency at 100% all the time rather than letting it ramp down. The two OSes also ultimately have different scheduling schemes which could be causing linux to put more pressure on various cores than what windows does.