This is a question I have been asked a hundred times and based on a quick Google search it looks like there are quite a few other folks who want the answer. How hot can my PC run before it is not safe anymore? We will start with why you would care how hot it runs. Some lots of reasons and high temperatures can cause all kinds of step in semiconductors. It increases the electrical resistance, reducing efficiency, it can speed up the degradation of electrical pathways within the component allowing errors that cause data corruption, and it can even, if the proper safeguards were not in place, cause low-temperature solder that is sometimes used to completely melt.
While powered on WD red hard drive can operate anywhere from zero to seventy degrees, which in their testing produces no undercover error and a GTX 780 ship an 80-degree maximum. NVidia theoretically allows up to 95 degrees but we found the actual limit to around 86 degrees Celsius.
If it says, it is okay directly on the manufacturer's website, why are more people still have confusions? This is because it is not quite that simple. Unlike the engine in your car, which uses a thermostat to maintain itself within a very narrow range usually would between 90 to 100 degrees Celsius, most PC parts don't have moving parts that rely on tight manufacturing tolerances and high performance lubricants to keep them functioning so they don't really have an optimal operating temperature. That means that while the hard drive with moving parts specified a maximum temperature for the other stuff, a maximum is specified and the minimum is not because you can pretty much run as low as you want.
With that said, lower is better if you are taking the appropriate precautions. For most people, you are not going to want your temperatures to drop any lower than ambient or the temperature of the surrounding air because below that temperature, water droplets forming on your components due to condensation becomes a major concern. Water is worse for your hardware than high temperatures. so here's a summary first check out the manufacturer's product page and then take a bad information with a grain of salt, if you're one of those people who believes in taking really good care of your stuff and you want to be sure that your hardware will last and be reliable. Keep in mind that the way manufactures rate their products is based on the way they expect most people will actually use them. They are not expecting you to still be using that CPU graphics card or hard drive in 10 years’ time and they certainly are not giving you a warranty that last that long. Therefore, they build some buffer into the numbers but they do not worry about those fringe cases too much.
So for added assurance take their number and building your own buffer that makes you feel comfortable.
