How do I know which power supply to buy?

[sdsumike619]

I'm putting together a system - I haven't a clue about how to buy a power supply.
Compusa told me one thing and fry's told me something else, so either one is trying to sell me something I don't need or the guy at compusa doesn't know... Is there a definitive way to figure out what I need as far as the PS goes?

So far for the system I have:

Core 2 Duo E6300
ASRock 775 Dual-VSTA
1GB DDR2 667 (I have to buy two 512 sticks right? Is there any other spec on the memory I need to look for?)
MSI TV-5200 AGP (from old system)
Two IDE hard drives (from old system)
DVD burner (old system, maybe)
Firewire drive (old system)

[Bodyslide]

The motherboard you have chosen just needs a 20-pin connection to get Power..

Here's one that should fit with no issues.

http://www.newegg.com/Product/Product.asp?Item=N82E16817153023

[Bullworth]

You can go to this site and use it as your starting point. Just to be safe I always buy a PSU that's 50 to 100 watts over my calculated needs just for upgradability and to make sure you won't be teetering between just enough and not enough power.
When you ask what kind of power supply you needs are you talking if it will have the connectors for the motherboard since AMD and Intel MBs are different or what exactly? Let us know.

[sdsumike619]

only $40?? sweet! I knew I didn't need to buy some $100 unit

This should fit in a standard ATX case right? Some of the reviews are saying it's a pretty big unit...

[sdsumike619]

I was just on newegg, and I started looking for a case. They sell case/power supply combos for pretty cheap. Should I get one of those, or get the pieces separately?

[Bodyslide]

I would buy the case and PSU seperate. However if your tight on Money get the Case and PSU and replace the PSU later.

Here is the case and PSU combo that I have Built about 10 PC's with. Good Luck.

http://www.newegg.com/Product/Product.asp?Item=N82E16811144124

[budz]

I'd suggest getting a TRUE POWERII ANTEC Power supply. If you can get the ANTEC power supply locally that would be the best way. In case there's any defect you can just return it to the store instead having to ship it back.

[sdsumike619]

Bodyslide, that case you linked me to, it has no fans

[Bodyslide]

Nope, it has none.

Up to 3 case fans can be added:
2 x 80mm - front (optional)
1 x 80mm or 90mm or 120mm - rear (optional)

[Wile_E]

On the power supply, look at the total amps of the +12v line instead of the total wattage. The +12v is what powers your hard drives and fans. Many people are fooled into thinking a 500w is better than a 400w just because of the wattage. The amperage shows the true power.

[sdsumike619]

Didn't know that,,, what should then wattage be under the +12v ?

I'm liking this one because it has 3 fans:
http://www.newegg.com/Product/Product.asp?Item=N82E16811208006

[SingSing]

Use Bodyslide suggestions which are right on the money.

[sdsumike619]

meaning his case suggestion and just buy the extra fans? I don't understand the whole +12v thing..what should I be looking for written on the side?

[Bodyslide]

You can get the fans for the case I linked to for less than 10.00...

[sdsumike619]

Will do, thanks =) With the case, mobo and cpu I'm right at $300 on newegg... this is turning out to be great! On to the memory....

[Bodyslide]

2 of these : http://www.newegg.com/Product/Product.asp?Item=N82E16835150053

1 of these: http://www.newegg.com/Product/Product.asp?Item=N82E16835150065

All for around 16.00....

[sdsumike619]

That 120mm fan you linked me to got some pretty bad reviews on newegg.. do you use this one?

this one leans more toward the 5 star end:
http://www.newegg.com/Product/Product.asp?Item=N82E16835200007

Will it work with your case rec.?

[TBoneit]

IMHO: Look for a power supply that is over 500 watts, has 20 and 24 pins Plus SATA drive connectors, 6 pin and 8 pin as well as 4 pin for mtherboard/video cards. Might as well future proof it. Get a decent brand. A cheapo power supply can fry the other components in the computer when (not if) it fails. I hate breaking bad news to customers... IE the PS went bad and fried the MB, Memory, Drives, Video card etc. And that all their data is gone unless they want to spend for recovery.

Personally I like a case that can take the larger fans, They'll turn slower for the same air volume and as a result run quieter and last longer. Why do you suppose Dells are so quiet, one reason is they use larger thermo speed controlled fans for quiet and longevity.

Also get a case with plenty of drive bays and decent metal. The cheap cases are tinny and feel cheesy. You can not tell that from buying online.

Personally again Buy the case and PS local so you can examine the inside and the fit and feel of the case. As someone else mentioned Antec is a good brand of PS. The cheap power supplies even feel cheap and light compared to decent ones.

Disclaimer: I repair computers and sell parts in a B & M store. I mention this because I dislike buying online. I even get my blank media when it is on sale in local B&Ms such as Staples & Best Buy. Typically Verbatim, MIJ Fuji/Sony discs. OTOH my suggestions are based on working in my present location since early 1996. Having studied Electronics for 3 years, Having used computers since before the IBM PC and starting out by building a XT Clone and then an AT CLone etc.

CHeers

[Skith]

Looks like a decent case. Has the necessities (good intake fan to cool HDs, and provide case airflow. Mid-rear exhaust. I would question the PSU though. It may work fine, but personaly I wouldn't want the heart of a system to be of questionable quality. Bad/Cheap PSUs can cause problems/instability and a failing or blown PSU can cause hardware damage. I am not saying the PSU will not work, just that you have to weigh the risks.

Good PSU manufacturers include: Seasonic, Antec (some models are better than others), Fortron (I hope I spelled that right), OCZ, PC Power & Cooling (one of the best, and you pay $$$ for it), and mabey a few others I am forgetting.

Look for Active PFC, I recommend a PSU with dual rails, each with a minimum of 18 amp +12. Any of the ~480+watt models from the above should suffice, if only one rail go for the highest amperage you can afford. You might want to go with a higher (watt) rated unit (which should correspond, at least somewhat, to a higher amp rating) if you plan on adding more devices, or plan to use the PSU in future builds. Also look for a higher efficiency rating. The higher the efficiency, the less power that will be lost to heat dissipation. Models with 120mm fans are a bonus and will be quieter, I would avoid fanless models.

Some other cases might offer additional features like:

- Support for drive rails. Basically you attach 3.5"/5.25" drives to a set of rails or tray that easily slides into and locks in the chasis drive bays.

- Tooless design

- Front USB/FireWire/Audio connections (the front audio connections don't work with add-on cards).

[jgombos]

The more power, the better. Don't worry about energy waste, because the PSU will only produce the energy needed to meet the demand. Too little power is a problem. I've had PSUs that could not meet the demand before, like in a SCSI raid system, and experienced strange problems that made it difficult for me to know that the PSU was failing.

Skith made a good point with the dual rail. Dual rail will ensure that if you do end up with more demand than supply, your motherboard won't be the device that gets cheated. Instead, it will be your drives.

Larger fans are quieter / more pleasant.

If you're on a really tight budget, slickdeals.net has advertised free PSUs twice this year. But the quality is poor. Some people who bought these Ultra brand PSUs reported DOAs, or PSUs that failed within a couple months. I bought one just to have as a spare.

[thecoalman]

I purchased a Antec truepower 2 last year, technical stuff aside it's quiet as can be. If all my case fans were as quiet you wouldn't be able to hear the computer. I swear it cut the noise level in half when I installed it.

[lordsmurf]

A lot of those no-name power supplies will die in a few years, or otherwise have issues. They cannot handle the power at a sustained level.

The old idea of heavier PSUs being better is still true too, to a degree. If you pick up some featherweight unit, put it back.

I like heatsinked units that have a single 120-140mm fan on bottom that sucks the air out of both the case and the PSU, and pushes it out the back of the unit. They are so incredibly quiet.

My last PSU was $75 for a 500W, and it works nicely.

Multi-speed fans can also be good.

[rallynavvie]

Power supplies are, to me, one of the most important parts of your computer. You'll find from other systems engineers/builders are of a similar mindset. Everything in your case is fed off that supply so if it takes a dump it has the opportunity to take everything attached with it. If you're lucky it'll just take itself out. Though I prefer to build my systems out of quality components, since I'm getting it cheaper than an OEM box anyway, there is a hierarchy of things that I can shave some cost off to save the customer money. Bottom of that list is the PSU.

For consumer use the Antec units have proven most reliable. Sparkle and Fortron are alternatives. The absolute best from my experience are PC Power & Cooling units, but you're paying for it. However any manufacturer can let a bad PSU out so you just have to be vigilant or get your PSU tested at a computer shop before firing it up.

I'm confused, that case on NewEgg that bodyslide posted says in the title that it has a 420W supply but the notes at the bottom say 350W. If there's a 70W differential with peak power then I'd be a little worried. Or even if it were a typo from the manufacturer just copying an older case description I'd still be worried. I have NEVER purchased a PSU in a case in my life.

[jgombos]

I purchased a Antec truepower 2 last year, technical stuff aside it's quiet as can be. If all my case fans were as quiet you wouldn't be able to hear the computer. I swear it cut the noise level in half when I installed it.

That's what I'm running. It's a very good PSU, but it will cost the OP ~$100 USD. It would be overkill if the OP isn't building something that needs high availability. IOW, I wouldn't buy a truepower 2 for a Windows gaming machine.

[Seeker47]

Power supplies are, to me, one of the most important parts of your computer. You'll find from other systems engineers/builders are of a similar mindset. Everything in your case is fed off that supply so if it takes a dump it has the opportunity to take everything attached with it. If you're lucky it'll just take itself out. Though I prefer to build my systems out of quality components
. . .
The absolute best from my experience are PC Power & Cooling units, but you're paying for it.

You are exactly correct here, and it is a false and risky economy to cut corners on things like the PSU.

Also get a case with plenty of drive bays and decent metal. The cheap cases are tinny and feel cheesy. You can not tell that from buying online.

Yes, one thing I really can't accept are all those cheap, flimsy cases. If it's a tower under your desk, your dog or a vacuum cleaner can put a nice dent in it with incidental contact. I have a Cal PC all-steel mid-tower, which isn't one of the most convenient or snazzy-looking cases. But it sure is rugged, surviving the Northridge Earthquake with stuff flying across the room and smashing down all around. Just a few paint chips came off. (That will give you some idea how long I've had it ! The case was not cheap, but I've replaced everything inside it three times, in various system rebuilds, so I'd say it was a good value long term.)

[tonyp12]

Ultra Wizard Black Case w/ 500w X-Finity Power Supply: $30 (after rebates)
http://www.radioshack.com/product/index.jsp?productId=2466310&cp

If you already have the case, a 500watt psu for $25 (after rebates)
http://www.radioshack.com/product/index.jsp?productId=2271458

Add this to get free shipping:
http://www.radioshack.com/product/index.jsp?productId=2211703

[TBoneit]

One reason I say a good power supply will be heavier than a cheap PS for the same watt rating. The good one will have larger heatsinks, dual fans and have some margin built in whereas the lightweight one may meet the PS rating when new and have no margin at all. Second difference in a good Power Supply versus a cheapo one is the quality of the cooing fan(s). A cheap one may have the fan die in a year and overheat to destruction. Another area of difference wires coming out of the PS in a good one should be wrapped for protection against fraying and to improve airflow, ala rounded drive cables. Having them wrapped makes routing easier as they are also generally longer so they can be routed out of the way. There will also be more drive connectors with a good PS. A cheapo PS will be shorter wires not wrapped, and just enough connectorsfor 4 drives plus one floppy.

One other thing you may not realize is that the same case may be different prices from different vendors simply because they also put different power supplys in them. I'm using a cheap tinny felling case for one computer because it was cheap, I put a good PS into it and because it has a handle on top so I can carry it back and forth easily (a previous requirement). My main case OTOH is a Lian-LI all aluminum that handles 12 drives total, all thumbscrews. The motherboard tray slides out the back, the bottom 5 drive holder slides out the front and is colled by two 3 speed fans, the other 3.5" bays slide out the front, four USBs in front etc. Cost $$$ but I've had at least four different MBBs in it and it is still like new. Quality can pay in the long run. rear fan. I've had this case as far as I can rmember since the days of the Athlon 1200 CPU and haven't done any fan changes and only vacuum the fan filter for maintenance.

Another place cheap is different in cases is the quality of the Paint itself and the fit of the pieces.

Good Luck

[julitomg]

Is there a way to determine how much power do I need for a given system? or just "get the biggest PSU you can afford" logic?
For example, i´m thinking about building a system with more or less the following components:
MoBo: ASUS P5ND2-SLI Deluxe(wouldn´t use the SLI feature, just one PCI Express video card)
CPU: Pentium D (3.0 or 3.2)
Memory: 1GIG(2 512 sticks) DDR2
1 PATA system HDD
1 DVD Burner
1 DVD ROM (probably a combo drive, CD burner, DVD reader)
2 (for the moment) SATA 2 HDDs for video storage
1 floppy drive or card reader
at least 3 or 4 case fans and harddrive add on fans
The PC will be used for video capture, editing, encoding and DVD authoring (also some audio and image editing, etc... but no web surfing, office, printing, etc..)
What would be my power requirements?(also considering I might add one or two more SATA drives in the future), will a 500 Watt PS do?

[rallynavvie]

Yes, 500W is fine for that rig and would probably have enough room for a second video card if you were to use the SLi.

[julitomg]

Thanks!