PC Power Supply; Screw Up? (GPU Related)

[outrun]

Okay here is what I did guys/gals.

I upgraded the power supply unit on a 4 year old Dell from the factory 305W to a 460W aftermarket midgrade unit. The reason was preparations to install an HD Card for possible Bluray capabilities. However, after I installed the power supply new information was found by me. Prior to the install my old readings showed that high performance GPUs were power thirsty from 350-450W+ requirements (ie Nvidia 8800+ & ATIs 4800) However, now I have started researching and found out the new stuff from NVIDIA (200s) and ATI (5400s)are incredibly power efficient with the power needs well below double digits! Plus they have the near 100% CPU offloading/acceleration making my old Pentium D usable for HD movies. I can put off the Core-i series or Duo a little bit longer then

Therefore, my tangent question is do power supplies internally vary their consumption? Or is the power supply always putting out the rated 460W? (I mean this similar in the way that a car's gasoline engine is not always putting out peak horsepower.) If it is then my belief is that I would be then wasting power equated by my electric bill. I can easily step down to a lower rated unit if need be.

 

[Colt45ws]

It will only put out the watts your PC is needing at that moment in time, which does vary with load.
What brand did you go with, by the way?

 

[cbear]

Watts=Voltage x Current. A good power supply will keep the voltage levels steady when the current demand goes up. Each voltage the PS puts out will have a max current rating. As long as you have enough capacity to drive everything that uses that voltage (-5,+5,+12, etc) you should be fine.

 

[Brons2]

If you just want a card to offload HD/Blu-Ray decoding to, those don't require all that much power at all. A lowly ATI 4350 can do it.

If you want a higher end gaming card, 460 isn't enough.

 

[Familyguy]

The newer high end video cards have indeed gotten more efficient, but you don't need very high end if you just want to excrete high-def video. As someone else mentioned any old ATI 4XXX board will more than suffice and will not require much in the way of additional power.

Also, there are motherboards out there with integrated ATI 4XXX video solutions. You could build a brand new rig with new power supply/motherboard/i7 for about $500 these days.

 

[Rand]

I'm not sure 500 is realistic for something with
a i7, 6gb ram, power supply, case, dvd, 200$ video card., hdd

500$ upgrade i7 + mobo + memory is certainly doable though.


as was mentioned a power supply capacity is just what it can output.. not what it does output.

 

[Familyguy]

Originally Posted By: Rand
I'm not sure 500 is realistic for something with
a i7, 6gb ram, power supply, case, dvd, 200$ video card., hdd

500$ upgrade i7 + mobo + memory is certainly doable though.


as was mentioned a power supply capacity is just what it can output.. not what it does output.


At Microcenter, a Core i7-930 is $199. Those things clock right up to 3.8-4ghz on the stock heatsink/fan. A motherboard with INTEGRATED HD-capable video chipset with an HDMI out is another $100. That leaves you $200. Another $150 gets you 6GB of DDR3 memory and you've got $50 left over for a 500W power supply.

Shave another $50-70 off if you decide on a Core i5 instead of i7. You could use that to purchase a brand new 1 terabyte hard disk to go along with the other stuff.

Totally do-able for $500. Hit www.microcenter.com or newegg.com and see for yourself.

Best,

 

[Nick R]

The important number on power supplies isn't the overall wattage. It is the +12V rated output. For example. I only have a 400W power supply, but it is rated for 30 amps (360W) on the 12V rail, which can easily power what I have in it, and more if I decided to upgradae to an Athlon II X4/Phenom II X4 which I am considering. Not to mention it is a very high quality power supply, with very high efficiency. (Antec Neo Eco 400C, 80plus certified)

 

[Familyguy]

Actually, if you are willing to consider an AMD processor, it's cheaper still. I was able to configure this machine on Newegg for $418.96. It would be only $279 if you went dual core instead of 6 cores.

6-core PhenomII processor @ 2.8ghz
motherboard with onboard ATI 4350, USB 3.0, etc
8GB DDR-RAM
500W OCZ power supply

http://www.newegg.com/Product/Product.aspx?Item=N82E16813157200
http://www.newegg.com/Product/Product.aspx?Item=N82E16817341016
http://www.newegg.com/Product/Product.aspx?Item=N82E16820231307
http://www.newegg.com/Product/Product.aspx?Item=N82E16819103851

Good times.

Edit: Here's the 2.9ghz Athlon II X2 for only $58.

http://www.newegg.com/Product/Product.aspx?Item=N82E16819103687

 

[Nick R]

Put in the AMD Phenom II X4 965 for $159 or something like that. That is very reasonable, and what I'm considering myself with an DDR2 supporting motherboard.

 

[Rand]

person
Originally Posted By: Familyguy


At Microcenter, a Core i7-930 is $199. Those things clock right up to 3.8-4ghz on the stock heatsink/fan. A motherboard with INTEGRATED HD-capable video chipset with an HDMI out is another $100. That leaves you $200. Another $150 gets you 6GB of DDR3 memory and you've got $50 left over for a 500W power supply.

Shave another $50-70 off if you decide on a Core i5 instead of i7. You could use that to purchase a brand new 1 terabyte hard disk to go along with the other stuff.

Totally do-able for $500. Hit www.microcenter.com or newegg.com and see for yourself.

Best,


while that may be true I fail to see the purpose of buying a core i7 and using built in video.

what sort of role would this computer be filling?

If I was going to use built in video I'd step down to something cheaper

 

[Familyguy]

Originally Posted By: Rand
person
Originally Posted By: Familyguy


At Microcenter, a Core i7-930 is $199. Those things clock right up to 3.8-4ghz on the stock heatsink/fan. A motherboard with INTEGRATED HD-capable video chipset with an HDMI out is another $100. That leaves you $200. Another $150 gets you 6GB of DDR3 memory and you've got $50 left over for a 500W power supply.

Shave another $50-70 off if you decide on a Core i5 instead of i7. You could use that to purchase a brand new 1 terabyte hard disk to go along with the other stuff.

Totally do-able for $500. Hit www.microcenter.com or newegg.com and see for yourself.

Best,


while that may be true I fail to see the purpose of buying a core i7 and using built in video.

what sort of role would this computer be filling?

If I was going to use built in video I'd step down to something cheaper


Do elaborate. Not everyone that needs cpu grunt also needs a $200 video card. And the integrated ATI 4300 video is fairly high performance for almost any task and capable of driving a 1920x1080 or 1920x1080 LCD effortlessly. You won't be able to play Crysis at 1920x1200 with all the eye candy on, but it's perfectly serviceable for gaming at 1280x800 or similar resolutions. It's overkill for any HD video usage like watching DVD's or Bluray content.

Best,

 

[Rand]

My point was why spend 300$ on a processor and mobo with built in graphics. Not sure what use you would need a core I7 for that a athlon II x4 combo at 150$ wouldnt fulfill.

I don't seem to be getting my point across clearly.. so I wont pollute the threat farther.

sorry about offtopic.

 

[1 FMF]

Originally Posted By: outrun

Therefore, my tangent question is do power supplies internally vary their consumption? Or is the power supply always putting out the rated 460W? (I mean this similar in the way that a car's gasoline engine is not always putting out peak horsepower.) If it is then my belief is that I would be then wasting power equated by my electric bill. I can easily step down to a lower rated unit if need be.


no. with anything electric regarding power supplies you can always and generally should go higher with the rating on the power supply. Because the rating is higher does not mean the power supply puts out that much all the time, it only puts out what the load draws.

you always want a psu, for anything, to be rated higher than the load it draws.

In your case regarding a computer, say your computer actually draws 300w of power under full load and you went with a 305w power supply, that is bad because you are running the PSU at 100% pretty much which will be load, overheat, and cause it to pop and die if it's not a name brand. The other very common thing when running PSU's near their rating is for voltage to drop and cause computer instability across everything. And having a psu rated just a little over your actual draw limits your upgrade-ability.

I have a asus p6x58d-e with an i7-930, a cheapo nvidia 7000's graphics card for now, and my system idles at 150-160w and under full cpu load pulls about 300 watts. I have measured it with a kill-a-watt power strip. I have a corsair 950tx 950 watt power supply. If and when I buy a gtx graphics card that pulls over 200w, I'll be up around 500 watts of power draw. What you can do is look at the power efficiency curves of PSU's if they are supplied by their manufacturer, corsair does, and choose one that has the highest efficiency at the load ratings you expect to be at most of the time but be high enough to cover your max draw. In my case my 950tx is rated for 950w continuous, is an 85 efficiency rated but their curve shows max efficiency at 475 watt system load, which i will probably be at with a new graphics card. This is how you would want to choose a PSU to get max efficiency and least power wasted.

what you should plan for is a PSU to cover the power requiremens of the graphics card you would like to upgrade to, specifically the amperage rating on the +12v rail of the PSU. This is the most important.