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General discussion

Power supply

by rbarkley Jun 15, 2005 10:35AM PDT

I am running an Athlon XP 2400+, with two optical drives, two IDE drives on IDE 2/3 and two IDE drives on Promise chip. How large should my power supply be? I am currently using a 400W, but it has been suggested that I buy a 520W - do I need this much? Just curious before I spend the money. Any input would be appreciated.

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4 Posts
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That's a lot of drives.
by r. proffitt Forum moderator Jun 15, 2005 11:04AM PDT

But a 400 should be ok unless you are having problems. If it goes unstable, the supply could be an issue since you are pushing it a little.

We figure about 20 Watts a drive so you have 120 Watts just for drives, about 100 for the CPU and board and a killer video could be 75. It's up there.

bob

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Power Wattage Calculator
by caktus Jun 16, 2005 6:25AM PDT
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Check real time usage
by John46947 Jun 19, 2005 4:32AM PDT

There are so many things to consider when estimating power requirements that's it's hard to know where to start. One of the often overlooked things is USB usage. So many things plug into USB and get their power from your power supply and that's in addition to what your basic system requires.

I have always taken the bigger the better approach but there is a way to be sure. You need to monitor real time power usage. Most motherboards come with a power usage/motherboard monitor. Well most good ones come with it anyway. If you don't have one then you can get one on the net. Here's an example: http://mbm.livewiredev.com/

I recently built a new system and I was having odd little problems but I couldn't isolate the cause. That's when I turned to the power monitor that came with my Asus motherboard. Sure enough it showed I was running into power issues. Asus has a real time graph that shows the power demands as they happen. My little graph was bouncing all over the place. That's when I ran out and bought this power supply: http://www.xoxide.com/ocz-modstream-520w-modular-psu.html Needless to say my power problems have been resolved. My little Asus graph now produces a solid line no matter what is running.

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USB Oddities
by John46947 Jun 19, 2005 4:54AM PDT

I wanted to expand on what I mentioned earlier about USB devices that most people overlook when considering power usage. There are all sorts of USB gadgets these days that rely on your power supply for their power needs.

Here?s a USB heating blanket: http://www.mib.co.jp/products/ohizamoto.html

USB Disco Ball: http://www.xoxide.com/multi-color-disco-ball-usb.html

USB Personal Fan: http://www.xoxide.com/xjog.html

My favorite a USB Cigarette lighter and cup holder: http://www.xoxide.com/xray1.html

The list goes on and on but I think you can figure out that a cigarette lighter and heating blanket are pretty extreme power monsters to add to a computer system. Other than the novelty factor I can?t imagine why anyone would consider such idiotic things for their computers.

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