You cannot exactly answer that question as the power load can vary depending on how hard the drives or graphic card are working at any particular time. All you can say it is less than the rating of the power supply otherwise you would have to say that HP put in a power supply that would be to small for the current hardware. No manufacture would want to do that unless they want their customers throwing nasty comments about their product and to many of these can kill a product. The designers would install a power supply for some future expansion. However, a person would have to know what kind of extra hardware you want to install. For example, do you want install a faster graphics card or a more powerful CPU either will increase power demands.