Why the huge power supply units?

[konsole]

I went on a bit of a rant on another thread so I decided to start my own post about this.

It's safe to assume that without water cooling, the most power hungry highest end stuff is the video card and the processor. The 4870x2 in crossfire and the fastest core i7 together use about 550-600W. All other powered items use peanuts amount of power If you just run a single video card setup with a mid-high range processor I really dont see how you can need more then 600W in your computer. So seeing people talking about picking up their latest 750W or 1000W psu to run their computer just seems outrageous to me.

This is the kind of setup that requires a minimum of 750W

intel core i7 965
4 sticks ddr3
2 4870 x2 running in crossfire
3 sata hard drives
2 dvd burners
3 usb devices
3 120mm rans
water cooling pump

and who spends $1000 on a video card setup? If you just run the 1 video card the recommended power drops down to 550W.

 

[ScOuT]

Most people know that you don't need a huge power supply to run a normal computer. Look at my computer in my SIG...I run a ton of stuff from an Antec 650w just fine. I know some people choose a little larger power supplies because of load and price. I would rather have a 750w PSU running 50% load than a 500w running at 90% load. The other thing is...when larger power supplies are recommended...there usually on sale or a mail in rebate and you get it for a great price. Why not get a little extra?

When you start talking about 1000w and 1200w...I agree with you, that's when it becomes too much. I could see if you were running three GTX 295

 

[Pck21]

Although I think you make some valid points here OP, the truth of the matter is the PSU is arguably one of the most important components in the computer itself. Having a quality PSU can make or break a system really. You want the most amps across the 12v rails and you want the PSU not to be running at full load all the time. It's fine to run it at 90% load some of the time (heck I recommend it!) but you don't want to be put unnecessary stress on the entire system.

Are 1000w and 1200w PSU's necessary these days? Maybe to those who are running above and beyond systems like water cooling and using tri-SLI set ups. But in effect, they are future proofing their system for years to come. Maybe in the next 6 months we'll see a GPU that has a minimum PSU requirement of 750w, then what? For the now, a 650w is fine. I got mine on sale with a rebate for $89.99, normally over $200. I want my PSU to handle any component that I throw at it and not even blink. The last thing I want to worry about is "Will I have enough power?"

 

[Computer_Freak]

Although I think you make some valid points here OP, the truth of the matter is the PSU is arguably one of the most important components in the computer itself. Having a quality PSU can make or break a system really. You want the most amps across the 12v rails and you want the PSU not to be running at full load all the time. It's fine to run it at 90% load some of the time (heck I recommend it!) but you don't want to be put unnecessary stress on the entire system.

Are 1000w and 1200w PSU's necessary these days? Maybe to those who are running above and beyond systems like water cooling and using tri-SLI set ups. But in effect, they are future proofing their system for years to come. Maybe in the next 6 months we'll see a GPU that has a minimum PSU requirement of 750w, then what? For the now, a 650w is fine. I got mine on sale with a rebate for $89.99, normally over $200. I want my PSU to handle any component that I throw at it and not even blink. The last thing I want to worry about is "Will I have enough power?"

one of the best ways to put it...

only prob with future proofing, they might change from 24pin...

 

[ScOuT]

Your right...I can do a PSU calculator and it tells me that 480w will run my system. Try to find me a 500w PSU with 2 x 6 pin PCI-E power connectors with a combined total of 36 amps on the rail. There are some 550w power supplies with enough amps on the rail to run my card...but below 550w...good luck

If you find some let me know, maybe I just missed them

 

[diduknowthat]

It's cause most people don't realize how little power their computers can run on. I've seen people run E6600, 2 gigs ram, HD 3870 250 watt SFX power supply. And guess what it works perfectly fine (I'm not recommending that you do this, just saying that it's possible).

I bet most people on this forum (barring the crazy SLI/Quad SLI rigs) can run their computers with a quality 400 watt power supply. The only reason I got my high powered one is that it was on a steep sale locally, couldn't resist .

 

[just a noob]

thats assuming that everything's stock, voltmod and overclock a pair of 4870x2's, and plan to be sucking down near 800 watts of power, and thats without an i7 overclocked, and when those get overclocked, they suck down lots of power, oh, and if you're wondering about a power hungry system, check a pair of 8800 ultra's in sli, with a pair of amd fx-74's, get into overclocking, and thats a good way to get rid of 1000 watts of power

 

[Computer_Freak]

● Intel Core 2 Duo E6400 2.13Ghz (@ 2.536Ghz, CPU temp: 35° Idle, 50° Load)
● Biostar Tforce 965PT
● 2x1Gb DDR2 800 RAM CL6 @ 942mhz
● GeCube ATI X1650 Pro 256MB (Getting a GTX295 next week!)
● Corsair TX750W
● Razer Diamondback 3G
● 6 x 120mm Coolermaster fans

Im gonna get a GTX295 as well

That will suck down about 550W to 600W easily. My current rig probably uses about 400W at load

Also, you dont want a PSU to be running at full, or 90% for that matter. You want it to be cool and efficient, at 80% or less, cause then you start straining your system...

 

[Pck21]

one of the best ways to put it...

only prob with future proofing, they might change from 24pin...

Aye that is very true as well. It's hard to judge the ever shifting winds that come with new technology. Hopefully PSU manufacturers will take into account that most people have the 24pin already...but who really knows.

● Intel Core 2 Duo E6400 2.13Ghz (@ 2.536Ghz, CPU temp: 35° Idle, 50° Load)
● Biostar Tforce 965PT
● 2x1Gb DDR2 800 RAM CL6 @ 942mhz
● GeCube ATI X1650 Pro 256MB (Getting a GTX295 next week!)
● Corsair TX750W
● Razer Diamondback 3G
● 6 x 120mm Coolermaster fans

Im gonna get a GTX295 as well

That will suck down about 550W to 600W easily. My current rig probably uses about 400W at load

Also, you dont want a PSU to be running at full, or 90% for that matter. You want it to be cool and efficient, at 80% or less, cause then you start straining your system...

That's a great rig you got there and you definitely don't want that thing starving for power, as you already know. Your system is a great example in this case between actual power consumption and the need for more power when the time comes.

If anything OP, you want your PSU to laugh when the system tells it "I need more power." Instead of trying to accommodate the system by only handing out enough power to handle the slightest of tasks, you want the system to have more than enough to go around and then some. However, there's a fine line between "more than enough" and "too much" power, which I believe is what the OP is arguing. It's a balancing act and when it's done right, you can tell the difference.

For example, my parent's computer only had a 250w PSU for the longest time. I put in a new video card and ram and everything was fine...until we played games. It would work for a while and then freeze. I thought we had a bad GPU but then I bought the PSU in my sig and gave my parents my old 500w PSU. Everything worked perfectly then. Can the computer "run" on a low wattage? Sure it can. The nail biting part is when you ask it to perform a load heavy task. Like I said before, you don't want to ask the question "Will I have enough power?" If you have to ask that question, then you probably don't, so take the mystery out of it and just get a decent PSU.

 

[konsole]

However, there's a fine line between "more than enough" and "too much" power, which I believe is what the OP is arguing. It's a balancing act and when it's done right, you can tell the difference.

yeah exactly. I'm not saying that you shouldnt get a larger psu then your computer needs at maximum load. I know many people around here that run ridiculous setups that require a minimum of 750W and so going 1000W for them is understandable. It's when people build their computers and feel as if they need a 750W+ psu when their system only uses 350W at load. Now for future proofing, ya you would probably be smart to get a psu thats a bit larger then what you currently need, but then again, you have to consider like what the other poster said that it can become outdated.

The only reason why I think its an important topic to think about is because there is a huge difference in prices between the different wattages.
for instance on Newegg

highest priced 500W: $130
highest priced 750W: $250
highest prices 1000W: $350

bought $100 per 250 watts
40 cents a watt?

someone can easily save $100 by choosing the proper size power supply

 

[Computer_Freak]

yeah exactly. I'm not saying that you shouldnt get a larger psu then your computer needs at maximum load. I know many people around here that run ridiculous setups that require a minimum of 750W and so going 1000W for them is understandable. It's when people build their computers and feel as if they need a 750W+ psu when their system only uses 350W at load. Now for future proofing, ya you would probably be smart to get a psu thats a bit larger then what you currently need, but then again, you have to consider like what the other poster said that it can become outdated.

The only reason why I think its an important topic to think about is because there is a huge difference in prices between the different wattages.

A core i7 920 uses 130W.

OCed, it would go to 150W.

A GPU connected to the mobo only uses 75W

thats 225W already (including the OC)

then add the HDD, DVD drives, fans etc.

Thats 300W for a normal PSU.

For it to run fine on load, you need 350W - 400W.

Having lets say a 8800GT, you will need a good 400W - 500W.

Then it just goes up...

That's a great rig you got there and you definitely don't want that thing starving for power, as you already know. Your system is a great example in this case between actual power consumption and the need for more power when the time comes.

If anything OP, you want your PSU to laugh when the system tells it "I need more power." Instead of trying to accommodate the system by only handing out enough power to handle the slightest of tasks, you want the system to have more than enough to go around and then some. However, there's a fine line between "more than enough" and "too much" power, which I believe is what the OP is arguing. It's a balancing act and when it's done right, you can tell the difference.

For example, my parent's computer only had a 250w PSU for the longest time. I put in a new video card and ram and everything was fine...until we played games. It would work for a while and then freeze. I thought we had a bad GPU but then I bought the PSU in my sig and gave my parents my old 500w PSU. Everything worked perfectly then. Can the computer "run" on a low wattage? Sure it can. The nail biting part is when you ask it to perform a load heavy task. Like I said before, you don't want to ask the question "Will I have enough power?" If you have to ask that question, then you probably don't, so take the mystery out of it and just get a decent PSU.

No need to bash My rig. Im just saying its a normal system (kinda like packaged systems...)

A good 400W will be ok, but its nice to have headroom, and extra power

 

[CdnAudiophile]

Why would you buy a power supply that just meets your needs? It is always good to have room to grow, and it's not like a 750 watt is going to draw 750 watts all the times. It just uses as much as needed so I don't know why you are getting bent out of shape over this. Why does it matter to you that people want to have some headroom?

 

[pies]

I got mine for around 100$ on sale so I figured why not.
My rig can run on a 550watt but now that I through a water cooler in there it's kind of nice knowing I'm covered.

 

[Twist86]

I only payed 80 for my 750w and it has made it through 2 system upgrades and will last through my next GPU upgrade as well.

I spent 80 bucks where someone who bought a 550 for 60ish had to buy a 650 for 70ish.

So the the person who bought "what he needed with a bit more" spent more then I did in the end.


Personally on the PSU you can afford to go higher....had the price been right I would have picked up a 1000w unit at the time but the deals were not as good.

That way when I upgrade to a I7 system next year I would save yet more not having to upgrade my unit.

 

[Okedokey]

There is quite a bit of ignorance here. A PSU's quality or suitability for a system has very little to do with the rated wattage. For example, i have seen 600W psu with only 16A on the 12V rail. Useless for any system describe above.

The real importance is the 12V rail's ability to provide sufficient amperage, at a reasonable stability and efficiency.

I went on a bit of a rant on another thread so I decided to start my own post about this.

It's safe to assume that without water cooling, the most power hungry highest end stuff is the video card and the processor. The 4870x2 in crossfire and the fastest core i7 together use about 550-600W. All other powered items use peanuts amount of power If you just run a single video card setup with a mid-high range processor I really dont see how you can need more then 600W in your computer. So seeing people talking about picking up their latest 750W or 1000W psu to run their computer just seems outrageous to me.

This is the kind of setup that requires a minimum of 750W

intel core i7 965
4 sticks ddr3
2 4870 x2 running in crossfire
3 sata hard drives
2 dvd burners
3 usb devices
3 120mm rans
water cooling pump

and who spends $1000 on a video card setup? If you just run the 1 video card the recommended power drops down to 550W.

Konsole, you really seem to not know what you are talking about actually. In fact I don't even think you have a clue.

Firstly, according to ATi's list of certified power supplies for 2 x 4870X2, not ONE, repeat not ONE is below 1000W. http://game.amd.com/us-en/crossfirex_components.aspx?p=3#ATI Radeon™ HD 4870 X2

You clearly don't understand the ATX 2.2 or EPS12 standards, nor the actual requirement of PSU to provide the required power in the right locations. Again, its not about wattage. Your recommendations are dangerous and very very ignorant.

 

[bamarammin87]

 

[konsole]

There is quite a bit of ignorance here. A PSU's quality or suitability for a system has very little to do with the rated wattage. For example, i have seen 600W psu with only 16A on the 12V rail. Useless for any system describe above.

The real importance is the 12V rail's ability to provide sufficient amperage, at a reasonable stability and efficiency.



Konsole, you really seem to not know what you are talking about actually. In fact I don't even think you have a clue.

Firstly, according to ATi's list of certified power supplies for 2 x 4870X2, not ONE, repeat not ONE is below 1000W. http://game.amd.com/us-en/crossfirex_components.aspx?p=3#ATI Radeon™ HD 4870 X2

You clearly don't understand the ATX 2.2 or EPS12 standards, nor the actual requirement of PSU to provide the required power in the right locations. Again, its not about wattage. Your recommendations are dangerous and very very ignorant.

so you think they recommend 1000W or more because a smaller size, say 750W cant supply the necessary amperage? I dont think they recommend 1000W for everybody, maybe I'm wrong, but it sounds more like a "playing it safe" type deal. Sure some people with extensive setups may be wiser going with 1000W but I still don't see why more basic setups, with those cards in crossfire, need more then 750W as long as the psu can supply the amperage.

explain to me why this calculator is recommending atleast 466W with nothing but the video cards in the system? Wouldnt it make sense that after adding the rest of the components to the system would bring the recommended wattage up to about maybe 600 or so? and you don't think this 600W psu could supply the necessary amperage? http://www.thermaltake.outervision.com/Power

 

[konsole]

ok here ya go

http://www.xbitlabs.com/articles/video/display/radeon-hd4870-x2_6.html#sect0

528 watts for 2 cards + 150 watts for a core i7 + 100 watts for everything else = 900 watts for whole system seems to be reasonable (1000 watts to be safe)
yes ATI makes sense with that.

for 1 card that number comes to about 515W.

and this is all if the person is running the power hungry radeon 4870 x2 and the fastest core i7.

Does 600W sound more reasonable for someone running a single 4870 (non x2) and say maybe a core 2 duo quad?
Reason I ask that is because no matter what setup they have I see the recommendation or the desire to go 1000W

Going back to my original point I just dont see why people go for the 1000W when running a single video card.

 

[Okedokey]

As i said before its not about wattage. The calculator is a basic idea, not a very technical approach, it doesnt factor in capacitor ageing or many other scenarios.

528 watts for 2 cards + 150 watts for a core i7 + 100 watts for everything else = 900 watts for whole system seems to be reasonable (1000 watts to be safe).

So you think constantly running a PSU at 90% e.g 900W / 1000W, especially when considering US voltages (115V) are lower and therefore less efficient - is a good idea? LOL

You are not factoring in temperature curves, capacitor ageing etc. Your original point was that a system that requires 45A just for the cards, plus a watercooling system and all the other gear would work on a 750W PSU. Thats bullshit. Even a 1000W system would be running in your words at 90%. Regardless, the issue is whether the 12V rail can handle the 45A + required and maintain the rest of the system, under load, at temperature, in a stable way over time.

 

[Vizy]

My computer ran fine on a 500W coolermaster. It didn't have more than 1 gpu connector so i went and picked up a Antec quattro 1000W. Kicks ass: