get as powerful one as you want. the first guy was a fool. i always use pc power & cooling units.

Shouldn't be any problem with getting a larger one.

Thanks you two. I was kind of thinking they were idiots especially after reading a few articles on the subject..

You can go as high as you want. It only uses what the system needs. Watch the size of the unit...some 700+ units are oversize (elongated) and can potentially interfere with your drives in some small OEM cases.

watts don't matter watts don't matter watts don't matter

any stupid PSU manufacturer can put a ton of amps on the 5V rail or divide it up into a ton of 12V rails that are insane to balance

do not use watts as any yardstick when selecting a psu end of story

He speaks the truth.

Unless you are running dual video cards, multiple CPUs, a bunch of hard drives, etc, just about any modern PSU will work for you. What's more important is if there is enough current running through certain rails to handle your hardware. Wattage means nothing if the rails you need don't have enough current.

And also, keep in mind EFFICIENCY. Typical wattage recommendations from a hardware manufacturer take into consideration the fact that many supplies have average or below-average efficiency. So they recommend higher wattage PSUs to compensate.

I'm not sure what the Dell guy was saying by "it can only handle 425 watts". The wattage rating of a PSU is the manufacturer-rated maximum power (i.e. current and voltage) it can produce. Not the amount of power it constantly provides. If an 800W power supply constantly provided 800 watts of power to a computer at any given time, the computer could get fried.

It's a Corsair 750 watt power supply. It's an XPS 420 system (Quad core, 8600gt graphic card, which I'm going to send back cause I don't play any games so I'm going to try Quadro card, 64 bit Vista 8 gb's memory) it came with 375w psu and upgraded to 425w cause that's what they said is the most it can handle. But I was talking to sales/customer service guy who assured me a bigger one would still work(without damaging anything) and that he knew what he was talking about (modifier and some kind of expert) so I tend to think he knows alot more than they do. At least I hope he does. Anyway thanks everyone..

fyi a Quadro is just a regular Geforce with different drivers, unless you do CAD it won't do much anything different for you

good choice on the corsair, though. though, you can do fine with their 450W, while it has a low "wattage" it's a single rail PSU with high amperage and can power even a 4850 system easily

also yeah, you can do whatever PSU you want as long as it physically fits inside the case. it just (/ is rated to) spits out power at a series of certain standardized voltages.

Quadro's are Workstation cards, and for CAD, 3D CG production industry apps, and things like that. They are optimized more for OpenGL than DirectX.

Thanks..

Pay attention to the size. A new psu might not fit in your Dell's case.

I think that is what the Dell guy was referring to. The rest have answered the Watt issue.

Dell is terrible. i had an XPS 200, and the PSU died. they insisted it'd be impossible for me to replace it on my own, so i built a new computer instead of putting up with their crap. a few months later i realized that the PSU size was a 2U server rackmount component. far from proprietary.

as to the OP, there aren't that many oversized ATX power supplies. i'd suggest looking for an "80+ certified" power supply. PC Power & Cooling offers several under the "silencer" brand name. Corsair also makes good PSUs. most decent-quality non-80% efficient PSUs are still very capable of being energy efficient, but usually only when they hover around 50% load. the 80+ certified ones tend to have a much wider range under which they remain energy efficient.

Dual physical processor boards generally use an EPS power supply. These are larger than the standard ATX PSU form factor. Mostly longer. The key thing is that they have the 24 pin, 4 pin, AND 8 pin power connectors. Large and expensive.

i dunno, i have a Thermaltake Toughpower 700W that has a 20+4 pin main connector an a 4+4 pin CPU power connector, standard ATX form factor (as far as i can tell, anyway) and both 8-pin (1) and 6-pin (2) PCIe connectors.

and my gigabyte motherboard is an LGA 775 CPU socket but only requires the 4-pin ATX CPU power connector.

go figure