power supply - New PC build, PSU Wattage confusion

I am building a new PC to use as a home media server.

My computer parts have arrived (apart from the CPU) and I intend to build next week.

I'm having some problems figuring out whether or not the PSU that I have will suffice. I ordered a Thermaltake case which comes with a 450W PSU.

I just opened up the case and on the side of the PSU, there's a table which says: DC output of 3.3V and 5V gives 150W max output power DC output of 12V gives 237W max output power (and 25A max output current).

The PC specs are as follows: AMD FX-6300 @ 3.5GHz 8GB Corsair RAM, 1600MHz 1x64GB SSD 2x3TB Western Digital Red hard drives (Might increase to 3 or 4 drives in future) 2x80mm fans

I thought the PSU was 450W (which would be enough). What are these other numbers that are on the side of the PSU?

welcome to SuperUser.

There are some great websites which have Power Supply Unit calculators. These will help you determine which capacity power supply to go with. Do a Google search for PSU Calculator

I would suggest using 3 tools and take the average. Of course, remember to take into account what you might potentially have attached in the future. If you're going to have devices like hard-disks or USB DVD writers attached to the computer from time to time, include these in as well.

In your case, you haven't specified which Video Card you're going to use, so I presume you're using an onboard graphics card. If this is the case, then 450W should be sufficient for your needs. I wouldn't hold it against you if you double-check that with the PSU calculators, though!

With the ratings that you've seen (the 150W max @ 3.3V) determines the maximum amount of power that can be distributed on that particular voltage "rail".

Computer components use a number of different voltages, and the power supply must supply each of these voltages to your motherboard. Your memory might only use 1.5V, for example, while your Video Card may need 12V (through an external connector). Your case cooling fans might use 5V.

In most cases, these are not particularly important. If your computer build is going to have an unusually large amount of devices that use a particular voltage, you might have to pay careful consideration to these numbers. For example, if you were building a beast of a computer with the 4 most powerful graphics cards you could get, then you might have to be picky about the maximum amount of power for each voltage.