I want a QUIET 500watt power supply - I think

[boe]

I think I'll want at least a 500watt power supply but I don't want to get more than I need since my PC is on a lot and don't want rediculous power bills.

I'm thinking about building a new system -
AMD x2
SLI or Crossfire - currently looking at x1900 - but waiting for the g71
2 350 GIG SATA2 hard drives
sound card
several usb devices.

I was looking at the Noisetaker 600W and 485 - not sure if the 485 is enough - I'm guessing it would be. I have a 350 watt enermax now that seems relatively quiet but as sizes change their may be a quieter unit. Are there any good PSU calculators? I know APC has a handy thing for guessing the right UPS based on the equipment you use.

Thanks for your help.

[Shining Arcanine]

You might want to reconsider. Your PC should not need more than 300 Watts, much less 500.

[frostedflakes]

Well, with X1900 Crossfire he'll surely want 500w+, as the video cards alone will be using 200w+.

But to the original poster, keep in mind that a power supply will only use as much power as it needs. With a 500w power supply, that's just a rating for the maximum amount of work it can do. If you're system only requires 350w, that's all it will use, doesn't matter whether it's hooked up to a 350w or 1000w power supply.

Enermax would be a fine choice. Might also want to look into the Seasonic S12 series. Just make sure it's compatible with the motherboard you plan to use, I think some people have had problems with the S12 and some DFI motherboards.

Do you plan to overclock? If not, 400w-500w would be more than adequate. If you're overclocking, I'd definitely get 500-600w.

[boe]

Well, with X1900 Crossfire he'll surely want 500w+, as the video cards alone will be using 200w+.

Do you plan to overclock? If not, 400w-500w would be more than adequate. If you're overclocking, I'd definitely get 500-600w.

Thanks for the reply - I do not intend to overclock.

I saw a gigabyte board that supports 4 video cards in SLI mode. If that works, I might want to check out something like that when they make it for AMD processors! I'd love to be able to run FEAR at 2560 x 1600 (native res) on my new screen with all the aa/af/soft shadows maxed out!

[omgy]

Here is a calculator
I'm not sure how accurate it is!

[El Doug]

Well, with X1900 Crossfire he'll surely want 500w+, as the video cards alone will be using 200w+.

Do you plan to overclock? If not, 400w-500w would be more than adequate. If you're overclocking, I'd definitely get 500-600w.

Thanks for the reply - I do not intend to overclock.

I saw a gigabyte board that supports 4 video cards in SLI mode. If that works, I might want to check out something like that when they make it for AMD processors! I'd love to be able to run FEAR at 2560 x 1600 (native res) on my new screen with all the aa/af/soft shadows maxed out!

I was myself pondering how to get SLI working with a dual-DVI monitor, and you hit it on the nose! Brilliant there - one set of video cards per DVI! Now i just need $2200 for the monitor, $200 for the mobo, and $1500 for the video cards! WooHOO!!!!!!!!!!!!!!!

[boe]

Here is a calculator
I'm not sure how accurate it is!

Thanks - I'm not sure how accurate either but I like the fact it has the more current MB,CPUs and video cards!

[El Doug]

that calc tends to overshoot a bit

[Tibors]

I put the values for my system in that calculator and it gives a wattage that is two and a half times as much as the highest peak I ever measured (from the wall!). So it is just as worthless as any other PSU calculator I have ever seen. The only good part about that page is:

... Total Amperage Available on the +12V Rail(s) is the most important, ...

The CPU is going to draw from one 12V rail, the videocards from another. Find the wattage for the CPU and the videocards you want, divide it by 12 and look at the PSU specs.

[Qwertyiopisme]

Here is a calculator
I'm not sure how accurate it is!

Thanks - I'm not sure how accurate either but I like the fact it has the more current MB,CPUs and video cards!

The "accuracy" of that calculater should be taken with an *extreme* pinch of salt (more like a bucketfull). For example

89W for a X3800+ (more like 30-40)
60W for a vanilla 6600 (more like 25-35)
10W for a stick of ram (more like 4-6)
20W for an audiocard with front panel (more like 5-10)

You shoudl probably take the output from that calculator and divide by 2-2.5 to get "accurate" results.

[AZBrandon]

The PSU calculator doesn't actually say that will be your consumption it says "Your Recommended Power Supply Wattage." I selected my own system's config (A64 3700+, 7800GT, 4 SATA HD, 2 DDR, 3 120mm case fans) and it suggests a 303 watt power supply, which seems very reasonable. The highest wall-draw I've seen so far on mine while gaming in Battlefield 2 is 170 watts, with a 5% overclock of the CPU. Typically it draws 160-165 watts from the wall while gaming, and 100 watts at idle.

[boe]

Typically it draws 160-165 watts from the wall while gaming, and 100 watts at idle.

Sorry for the newbie question - but how do I find out what my system is using?

[frostedflakes]

Yeah, as with most calculators, that one tends to over-estimate power consumption quite a bit.

It's more work, but your best bet would be to dig around review sites, look up actual measured power consumption for your specific components (not manufacturer ratings, which are typically worse-case numbers not achievable under normal usage), and use those as a basis for your power supply decision.

Xbit Labs is one of my favorite tech sites, as they go the extra mile to take accurate measurements of power consumption in their reviews and articles. They are the only site I know of that actually measures power consumption of video cards through the AGP or PCI-E slot and external power connector(s), as opposed to at the wall (which is not completely accurrate, as PSU inefficiency is factored in as well).

[StarfishChris]

Typically it draws 160-165 watts from the wall while gaming, and 100 watts at idle.

Sorry for the newbie question - but how do I find out what my system is using?

You need a power meter (for example the Kill-a-Watt or Power Angel) or make your own.

[stupid]

I think I'll want at least a 500watt power supply but I don't want to get more than I need since my PC is on a lot and don't want rediculous power bills.

I'm thinking about building a new system -
AMD x2
SLI or Crossfire - currently looking at x1900 - but waiting for the g71
2 350 GIG SATA2 hard drives
sound card
several usb devices.

Here's a link to Xbitlabs.com that will give you the power consumption estimate of the Athlon 64 3800+. Note that they were not testing an actual 3800+ , but a 3500+ clocked at 2.4GHz (the equivalent of the 3800+).

This link will give you power consumptions of some current gaphics cards.

[AZBrandon]

What StarfishChris said; I'm using a Kill-A-Watt. You can find them for $30-35 or so mail-order. I love mine!