Guide for Selecting a Power Supply

[Raben]

HP Pavilion Elite HPE-560z is the model I recently purchased with phenom 6x 1090 3.2 gh, ATI 6570 2gb and 16gb ram TB HD.

I noticed that the stock power supply is 300W and I am concerned if this will be enough to run this machine.  Anyone?

From AMD website

System Specifications for AMD Radeon™ 6570 GPU:

• PCI Express® based PC is required with one X16 lane graphics slot available on the motherboard
• 400 Watt or greater power supply recommended (500 Watt for AMD CrossFireX™ technology in dual mode)

Why does HP allow this build model with a stock 300W power supply?   Must I buy a better PSU just to run the video card on recommended performance?    Not to mention the processor uses 125W by itself...

Why HP... why....

[Big_Dave]

Hi Raben,

HP selects a power supply sized based on HP's components for a particular model PC.

[Raben]

Yes I figured that when I see that the 580 and 590 have a 460W.  The 500 and 560 have 300W.   Take notice that THIS model line is under the "HIGH PERFORMANCE" section of desktops. 

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HP should add power supplies to the customization part of buying their computers because gamers demand more power for their machines, heck not just gamers, anyone!

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HP you need to do this so your customers dont have to go out and upgrade the power supply right after they buy your "High Performance" machines just to take advantage of the high perfmance potential. 

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I suppose this means Im buying another power supply unless I want this computer to run like crap.

[Big_Dave]

Raben,

I agree with your suggestion that HP have a configuration option to select a bigger power supply.  However, a bigger power supply will lead to more heat inside of a smallish cabinet which might cause premature electronic component failures.

[JNagarya]

That is lame.

What HP shoud do is include all components necessary to both meet the purported specs and performance claims, and so the machine runs efficiently.  If that means a bigger box, which is not a big deal, then it's a no-brainer that that should be the reality.

Instead, they sell machines with specific specs -- and claims.  But in order to actually achieve the best from the machine, one must upgrade one or more components.  Some of the costs of the upgrades are in effect hidden costs.  So HP sells machines which they claim will perform up to a particular margin; but if it does it is marginally able to do so.  Then if one decides to upgrade in keeping with HP recommendations --- a better video card? -- then one must also upgrade the power supply, which HP doesn't reveal even at that point.

So HP sells machines with the promise that they can be upgraded -- better video! -- but doesn't reveal that the upgrade of video card will cost more than just the video card.

[SkipDaddy]

I have a Compag Presario CQ5320f and recently added a nvidia 8800 card so I could have two monitors, but it seems to be needing more power than the stock PSU.  I needa 400-500 watt PSU, but can't figure out what is a safe and cheap PSU to pick for this.  Any help?

[Big_Dave]

SkipDaddy,

You should open up your PC and measure the physical dimensions of your power supply.  Here is a list of things to consider:

1. Specifications
2. Total wattage - important
3. 12+ volt amperage rating - important
4. Modular - not mandatory but I like the flexibility
5. Warranty
6. i7 and SLI ready
7. Efficiency rating
8. Cost
9. Physical size -- standard ATX PSU is 5.5" by 5.9" by 3.4" give or take a few tenths
10. A single 12+ volt rail is a better choice.

www.newegg.com has lots of PSUs choices.  Corsair, OCZ, Rosewill, Thermaltake.....

This 500 watt Corsair is a quality PSU.

[SkipDaddy]

It's the connectors that always throw me.  I guess I could just take the whole thing out and hit the local microcenter with it, but I was hoping someone had already replaced one so I know an exact model.

[lfbb73]

Hello,

I have an HPE-310PT with a 460W PSU and a GTX 260 graphics card (Max Power=182W, Minimum Recommended System Power=500W). I've been running this computer for 6 months without a single problem and a few days ago I discovered that my PSU doesn't fit into the 260 power demands. I don't understand how the 460W PSU can handle the GTX 260. I tested it with programs like 3DMark, FurMark, etc, without a single problem. My PSU shows in the sticker that it has 3 12V rails (+12Va=18A ; +12Vb=15A ; +12Vc=8A). A power supply for the 260 needs to have (in total accumulated) at least 38 Amps available on the 12 volts rails(18+15+8=41A), no problem here. My doubts are on the wattage, what can you say to me about that?

P.S:The 260 card doesn't support DirectX 11 so I have already ordered an Asus GTX 460 1GB - a reference card - which I expect to work fine since is less power demanding than 260 (24 Amps on the 12V rails) and, beside that, according to Nvidia, only needs a 450W PSU.

By the way, here is a GPU-Z image of my gtx 260:

[Big_Dave]

HI,

HP uses OEM video cards made to HP's specifications so they may not be the same as a retail video card. The power requirements for many of the HP OEM video cards are at times different compared to a retail card.

Most retail GTX 460 video cards require two 6 pin PCI-E power connectors.  Your power supply may only have one.  You need to check for an extra PCI-E 6 pin connector. Otherwise, this means that you should make sure to balance the power draw for your video card across the rails.  This is a reason why I prefer to use a single rail power supply.

The maximum sustained power draw (continuous) is an important factor with any power supply.  Ohm's law is P(wattage) equals I(amperage) times E (voltage).  P=IE   The internal components in the power supply, particularly on the load side will have an big influence on the efficiency and continuous power rating.