Could somebody please explain to me?

B

BaLaClavaAa

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Jul 12, 2007
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I'm going to build my pc, and I was wondering what sort of difference there is between lets say a $30 500Watt PSU and $100 500Watt PSU? Also what are "rails"? Thanks
 
The $30 500W probably isn't really 500W continuous. Most of the $30 500W power supplies I've seen are actually 350W continuous, 500W peak.

Also, a $30 500W will likely be less efficient (converts less DC power for the same amount of AC power consumed) and probably doesn't have active PFC (corrects poor power factor for lower VA.)

Odds are also that the $30 power supply will have a good deal of ripple and noise on the output and could damage your components over time. Some don't have appropriate protection in place that should allow the power supply to shut down if there is a short, over or under voltage or an overheating condition.

"Rails" is just a term we use to describe each DC output of a power supply. A power supply has an AC input and several DC outputs. +3.3V, +5V, +12V, etc. Each of these are called "rails."
 
Ok thanks, I think that pretty much sums it up nicely =D.

So sounds like I should go with something with a bit more quality?

So sounds like whatever I get needs to have PFC, check reviews for true wattage, and power shortage protection (what would this be called btw)?

And what the standard number of and voltage of rails that should work with pretty much whatever I build?

Thanks again!
 
Ok it seems like I should be doing this bit last, once I choose everything I'm putting into it :rolleyes:
 
You should probably spend a minimum of $60 on the power supply. If you state your components we can help you for the best one at the lowest cost.
 
Haha thanks :)

Well to be honest I don't know what I want to get yet (mobo and processor and case)... I don't even know how to figure out what I need because there are just so many things to choose from.

But I'll probably have:

2GB DDR2 Ram
Radeon 1300x Pro 256mb DDR2 pci-e (or something similar)
My old Sound card
500Gb SATA HD (and maybe a second 30gb one, but probably not)
x2 DvD RW Drives
Floppy Drive
either a duel core or the Athon equivalent (can't narrow it down much more then that)
and a bunch of fans

Maybe I should move this to general and rename it "Tell Me What I Want" =] lol
 
1. check the stickies here. There is one thread which recommends brand names to stay away from. STAY AWAY...very far away.

2. If you are not an OC'ing type enthusiast, then don't spend a fortune on it. There is no good reason for it. If you are just building a PC and don't plan on heavy tinkering...get what you need and avoid the "bad name" list. This should put you in the $60 category based upon what you've mentioned so far.

3. Figure out how much power you are going to draw (see the stickies around here) mulitply x2. Then go to newegg and start limitig your list down based upon the above rules. You should be able to find yourself the PSU you need and learn a bit more.
 
Xclio and Enhance make fairly high quality, not too expensive units. I'd suggest you go with one of them if you won't be OCing and don't want to spend a lot.
 
puffcap said:
Does OC really up the power requirements that much?
Click to expand...

In short, yes.

EDIT: Perhaps I spoke too soon.

I just ran Orthos and loaded my CPU, used my UPS to check load at the wall -- 270-280watts at 3.2Ghz which is a 1.07Ghz OC from 2.13Ghz stock, or 50%, just running Orthos with small FFTs and standard background processes.

I then rebooted, went in to BIOS and set the FSB back to default, with default dividers so everything is running the same speed as before except FSB and the CPU itself -- same 800Mhz DDR2 on the RAM, etc. Got 240-250, varying.

So around 20 watts for a 1Ghz OC. Not the kind of numbers I expected. A far smaller difference, in fact, which is obviously a good thing, but my CPU seems to be a reasonably good OCer, it deals well with low vcore, and OCing is a hit and miss kind of thing, so these results may not be at all typical, your mileage may vary, it could explode and kill your dog/cat/fish/fiance/whatever, I withhold all responsibility in this manner... etc.
 
BaLaClavaAa said:
I'm going to build my pc, and I was wondering what sort of difference there is between lets say a $30 500Watt PSU and $100 500Watt PSU? Also what are "rails"? Thanks
Click to expand...

when it comes to power supplies, you get what you pay for, if you dont mind having a power supply fry your hardware, then try something in the 30 dollar range.

power supplies should not be skimped on, buy a dam good one like PC power and cooling, seasonic or FSP.

dont buy a power supply for lights and bling bling either, do some homework on the web.

I have built many computers and all of the builds with pc power and cooling units in them have NEVER failed.
 
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