The power supply came with two. I was surprised but not hurt to see that. I have two top rear case exhaust fans; one green glow and one blue glow. At night with the lights dim I can look at the wall and know that those fans are still under power. I have a lower front case intake fan. My CPU and my Video Card both have heat sink cooling fans. BTW open your case periodically and take a peak you will probably find that heat sinks love to accumulate dust. My Hard drives are not super drives, however if I were to install a hot hard drive, I would attach a two fan HD cooler to it

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