CPU's do not whine. What is probably causing the sound is the coils on the toroidal inductors on the motherboard vibrating at ultra-high speed. They are supposed to come with a layer of lacquer on them so they don't move, but in some cases the lacquer is too thin or fails. I have had the same problem on several of my desktop systems and inside several power supplies, and this is easily fixed by putting a dab of hot glue on the inductor. The reason this appears to be cpu specific is because the inductors are in the vcore voltage regulation circuit, which means that depending on the cpu and power draw, they will vibrate at different frequencies. This is what they look like I almost guarantee you that is the culprit, not the CPU which has no parts which can move or emit noise. The only time I've ever heard a cpu make noise was when I popped the heatspreader on an old Pentium 4 off because I had it at -64 degrees celsius under a custom built phase change cooling system!