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How come loaded OEM PC's have only 150watt PSU?

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Beast Of Blight

Disabled
Joined
Oct 17, 2002
Location
Orange County
I am curious, Whats the point of having and/or making a 550watt PSU when a loaded OEM machine can run decently off of a 120-150watt PSU?

Just curious.
 
Bigger is better regardless of whether it is or not. I bet that 9/10 people who frequent these boards have more power than they really need. I know I do.

I just checked out Dell's page real quick and I see a 250w PSU in the Dimension 8250.
 
And also, most OEM's don't really pack in the fans like we do. Almost all have 2 fans max, and I can guarantee those aren't high powered fans and HSF's like delta's, etc.

You could probably get by with a smaller one but it just isn't worth it.


-CPFitz-
 
i got an idea...

Go get you a dell, and you'll find out :p


*edit*

ok, so i felt a bit of a smarta## for that... so i'll elaborate a bit, the point of building yourself, is to use bigger better components than those guys do, for a better faster more stable system and cheaper to boot. you want to use bigger better stuff?? you need bigger better power. easy yeah?
 
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CChaos said:
Bigger is better regardless of whether it is or not.

Bingo! We have a winner. We all know that the only salvation comes from really high or really low numbers... heh.

The truth is a 350 Fortron/Sparkle will power virtually any PC that does not have a huge drive array, and the 400W version will take care of basically anything else. Actual power consumption lies at a much lower level than is popularly conceived. Quality is the important thing in a supply, I recommend either one or the other Fortron/Sparkle's or an Antec True Power 380 or 430 for 99% of all cases. You just don't need any more than that.

We at all times need ot excercise a bit of reason when making judgements though. Although a very capable unit, the 300W Fortron/Sparkle only saves you 8-11 dollars as compared to the 350 version. Obviously this is 10 bucks best not saved. As well the 400W version costs 25-30 more than the 350, so we want to think long and hard about whether actual current draw really mandates it.

Erroring on the side of caution does have merit though. If a person wishes to spend the extra for the 400W models I don't discourage it even though the 350 resides in my personal rig. But supplies larger than the 400 Fortron or the 430 True Power really are a bit silly, and provide no return on the additional investment in all but the most extraordinary situations.

And understand that modern IDE drives and especially fans draw very little power, just the fact that we tend to have a few extra of each doesn't materially alter the load placed on the supply. While I don't recommend the 250 Sparkle because it saves very little money compared to the 350, the truth is that even this unit will power 99% of the rigs here with zero drama.
 
OEMs know exactly what is going into their computers, so they can calculate how much power will be used and how small of a power supply they can use. I've heard of people overloading their power supply by adding new drives, video cards, etc.
 
There have been so many "Blah Blah Blah 550W PSU-What do you think?" discussions in this forum I've put this chart from Tom's into my favorites folder just so I don't have to look it up every time I need it.

This is a great reference for how much power each component in your computer will consume, and a great example of just how much stuff you'd have to cram into your case to tax even a 400W PSU.

Look at everything on that chart. With four hard drives, two optical drives, a loaded motherboard, Ti4600 video card, and a full compliment of PCI cards and AGP/Firewire devices, the total draw is 355 watts when everything is running. What are you going to drop in your rig to take that to 500W? Another four hard drives? Fifty fans? A pair of 60 watt light bulbs?

Juliendogg, with all respect, I always though the point of rolling your own was to do it smarter and better. Big is easy. Anyone who's caught a few episodes of Sesame Street can point to the big numbers. Big qualifies you to sell HP's at Best Buy and answer the phone at Dell. It doesn't mean you know jack about computers.

I know Larva is old enough to remember that back in the day a 300W PSU was usually called a "server power supply" because that was the only place they were used. The only time you saw anything bigger than that (for years the biggest I ever saw was a 400W) was on a dual-proc server or workstation rig. And as Larva notes, that was when drives and CPU's consumed substantially more power than today.

So to see someone with a classic desktop PC configuration (single CPU, one or two hard drives) declare they "need" a 500W power supply-its a joke. Its the PC equivilant of the guys who slap a huge wing on the back of their stock Civic.


BHD
 
Heh, love the sesame street reference.

The truth is I've been building PC's en mass for long enough that for the first 5 years I did I laughed whenever customers insisted on a 300W power supply, as it was ridiculous overkill. It was not until the advent of the ever so thirsty Athlons and the comming of the coppermine P3's that even 300 watts was in any way needed. Power consumption has risen since that time, but so has the output of a (good) power supply. As older supplies died under the stress all the reputable manufacturers have beefed up their units, even at the same nominal total wattage rating. As such a 350-400W model of modern design is certainly adequate for desktop machines of even very large porportions.

The only real exceptions to this rule are if you are running TEC's or water pumps, a block's worth of Christmas lights, or a toaster oven off your PC's main supply. It's hard to stack enough necessary PC components on a single supply to tax a 400 Sparkle or a 430 True Power, but you can easily get into trouble if you load up on the unnecessary.
 
Juliendogg, with all respect, I always though the point of rolling your own was to do it smarter and better. Big is easy. Anyone who's caught a few episodes of Sesame Street can point to the big numbers. Big qualifies you to sell HP's at Best Buy and answer the phone at Dell. It doesn't mean you know jack about computers.

Haha, very coy. "smarter and better"... i'd agree completely. i was only making a point. The fact remains, if you're going to run hi-end agp graphics, fans, lights, more than 2 hdd's all the goodies, and overclock, you'll never hurt anything by having to much power, now... would you want to remove your psu and replace it with a 150w from an OEM gateway comp? I seriously doubt this as i know that i certaintly wouldn't. I don't get on the bandwagon with folks who are going out and spending 100-150 on a high end psu, i went with the sparkle. I had the extra $ so i got the 400w over the 350w, no one can argue that a true 350w couldn't handle my comp and more. I wouldn't even want to.... But the extra wattage from the 400watter is there if i need it, and as the psu is never actually pushed, it runs quiet and cool. Nice huh? I thought so ;)
 
I've always thought these big bad power supplies are overkill too. I have my 3 custom built PCs, but I also have a Gateway 2.4Ghz P4, with a DVD drive,CDRW drive, 256MB DDR, 120GB HD, ATI 9700Pro, SB Audigy, Floppy and modem. I've also added a rear fan to the system.

All running on a 160watt power supply. It has been running non stop for about a month crunching seti.
 
OEM pc's has real numbers on p/s, your noname 350 can be 150 too. OEM pc's are also not _that_ loaded.
 
My God! Just do the math and figure out what power you need for your system. I am sorry to come out of the woods to say this, but you can debate this all you want. All I need to do is figure out what I plan to have and do the MATH! How many of you actually do this and and are satisfied with PS purchase. Enough said, I'll go back to the woods.:mad:
 
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