I have a custom water loop an ambient temperature inside the house is 22 Celsius my Loop Idol runs in about 27 Celsius and that's with tons of radiator space I would say 40 Celsius is good for you given the ambient temperature inside the house I also have it at 1.35 volts working with a 4790k at 4.7 gigahertz if you're overclock you will see higher temperatures even at idle all this is including that your Ambien temperatures are high at 92 degrees Fahrenheit