What is the point of doing post without the CPU? You would want to connect all of your components. Jay did one time put just 1 stick of ram GPU, and CPU, but when he locked his system under water loop he discovered that RAM slots 3 and 4 don't work and he couldn't install all of the memory kits. The point of the test is to save you time if something doesn't work, so you won't have to pull everything out of the case, and in the worst case brake down hard loop.