Recommend a Cool quiet PS

[BlazinTy]

Im in the process of building a new computer and have a few questions about the power supply.
This is the rig I'm thinking of building
Either a e8400 or a quad haven't quite decided yet.
x48 chipset mobo (in case I decide to go crossfire)
4 gigs ddr2
3-4 Sata HDs
Sata burner
either a 4870 1gig variant or maybe a 4870x2 when they come out
antech p182 case

My questions are these.
What kind of wattage am I looking to draw from this rig at load?
Is it better to get a larger power supply that is the most efficient at load? For instance a zalman 850watt that looks to be most efficient at 400-500 watts.
Is there more heat generated from a larger power supply in which wattage goes unused or does it only draw as much power as it needs from the wall.
In order of importance to me is it the most quiet followed by heat generated, efficiency and finally I would prefer a modular unit.

I was looking for a powersupply that would'nt ramp up so much under load. For instance a Zalman 850 which I am told is the most quiet and cool or perhaps a corsair 1000w. Or am I completely off base and should be looking at a 620hx corsair?

 

[yhelothar]

I was in your shoes shopping for a cool and quiet PSU just a few months ago.
First thing, make sure you get an 80+ certified PSU. This higher efficiency means it doesn't need to use as much power, which in turn means cooler and quieter.
Another factor that you probably already know about is that you would want to get a PSU that runs optimally at the power level your computer operates at. My system with a E6300 overvolted to 1.35V, 4GB DDR2, 3 hard drives, 8800GTS graphics uses about 150w idle and 180w full load.
Here's a great article about system power usage and power supply optimal efficiency

SilentPC Review has a very nice guide on silent PSUs

I ended up with the Corsair VX450W. The 450W was very efficient for running my system's power requirements - much more so than higher wattage models.

It was only $65 after $10 rebate. Considering the enermax 80+ 400W version costs $100+, I couldn't pass up the corsair.

 

[bob8701]

4870 or 4870*2 may required high current from PSU, 600 Watt should be enough for you, 850 watt seems over kill.

 

[Zap]

Originally posted by: bob8701
850 watt seems over kill.

Not if he's getting an x48 chipset board for possible Crossfire in the future. Crossfire 4870 will probably be pushing a quality 600W unit pretty hard, let alone crossfire 4870x2, 3-4 HDDs and possibly a quadcore (and possibly overclocks on everything?).

 

[yhelothar]

Nah 600W would be perfect.
With all that, he'd probably be pushing 300W, which is 50% of the 600W.
This means the 600W will use less power than the 850W... and thus creating less heat, which means cooler and quieter.

If you want an awesome cool and quiet, and very powerful PSU, it's this one.
Enermax Modu82+ 625 Power Supply
If you look at the chart on this page you'll see that 600W's peak efficiency is at 50%.

 

[BlazinTy]

So are you saying I should be looking at a corsair 620hx or 650tx? Are there any cooler quieter brands that I should be aware of? I dont want a fan that ramps up and is noisy.

 

[yhelothar]

Oops the code was messed up in my last post. I just fixed it. Check it again.
Look at the silentpcreview chart.
I think the corsair 650TX is the best deal at $90 AR at newegg.
The Enermax Modu82+ 625W looks to be the ne plus ultra though, but at $165, and it's just slightly more silent.

 

[BlazinTy]

Thanks for the chart but looking at all those corsairs and enermax they seriously start to ramp up after 50% becoming farily loud. According to anandtechs review of the zalman 850 it doesnt start to ramp up tell 500 watts which if I want some breathing room seems like the one I should get. Thoughts?
Also do the higher wattage psu's output more heat? Or does it only draws what it needs.

 

[Zap]

Originally posted by: BlazinTy
Also do the higher wattage psu's output more heat? Or does it only draws what it needs.

Only what it needs. Generally speaking any PSU will pull as much power as your computer uses. Of course in RL there are differences like efficiency, and the fact that PSUs are often not as efficient at lower outputs so a low power draw system would pull more power on a high wattage PSU (but we're talking maybe 5-10W?) than if it were on a lower wattage PSU.

There are some PSUs on the market (BFG ES-800 being one of them - not that I'm trying to shill) that doesn't take that kind of efficiency hit at low power draw.

I think BlazinTy needs to determine his future upgrade goals because I'd hate for him to get a 600W PSU now and in a year decide he really wants to upgrade to two 4870x2 in Crossfire. Either he plans for that eventuality by buying a higher capacity PSU now (Corsair TX750, BFG ES-800, Tt Toughpower 850, etc.), resigns himself to the fact that he may have to upgrade PSUs if he goes that route, or resign himself to planning on NOT ever going to two 4870x2 cards in the future.*

*Why I say this is that most likely the 4870x2 will have at least an 8 pin PCIe and a 6 pin PCIe, which means the card has the potential to draw up to 375W each (150W 8 pin, 75W 6 pin, 150W PCIe 2.0), though most likely it will draw between 225W and 300W (75W PCIe for backwards compatibility, 75W for 6 pin, 75-150W for difference between second 6-8 pin). Even at the minimum two of these will draw 450W and that's before the CPU, HDDs or anything else. While a good 600W PSU still may power it, that's like running your car at redline all the time. Might work for a while, but who knows what that does to longetivity.

 

[charlietee]

The Corsair 620HX or 650TX will easily power your system.

And they both are very quiet.

Great bang for the buck supply's

I used to use only Fortron and have switched to Corsair.