PSU Advice

[Frank Marino]

I was reading http://www.tomshardware.com/2006/02/07/5_power_supplies_get_the_full_juice_treatment/ on power supplies today, and it brought up some questions.

Right now, I've got my case's stock 350W PSU in my system. Because I've got a pretty lightweight system, (6600TG x1, AMD64 3200+), it seems to do the job for now. In the not-too-distant future, I'd like to jump up to a 7800GT, but I'm not sure how to guage my power consumption.

My motherboard has a simple program that tells me the voltage that 12V, 3.3V and 5V are running at, but I don't know how to "read" these numbers.

What are the major indicators that your system isn't getting enough power, or are there any? What major systems to these three voltages cover? If a system gets insufficient power, is there risk of damage? Is there a way to measure the general power consumption of the system?

Also, I've noticed that some PSU's, like Coolermaster's, come with front-bay displays, are these just for show, or has anyone found these to be useful?

Thanks in advance for any help. [/url]

[PUTALE]

Well, one of must easily way to tell whether your system is getitng enough power is the isntability. if the system random reboot all the time, it's a indication that maybe the psu is not stron genough.

There are programs otu there that can detect the general usage of the system (some are estimating to how much psu you would need, some are actaully detecting the usage of the wattage. but the easiest and the best way to know the power is using a voltmeter).

I think 350w powers your setup fine, but if you plan to go to 7800GT, you probably need to consider getting a 450 or higher wattage, also you should look for at least 25amp or more on the 12v.

The truth is that the amp on each rail is more important than the wattage as the gfx consumes the 12v more. Just get a reputable maker, such as antec, seasonics, enermax and you should be fine.

as for the front bay disp[lay, I thin most of these are for shows only.

[Frank Marino]

Thanks Putale, what are rails? That kept coming up in that article and others. Is that just the term for a particular power source (12v, 3.3v, 5v)?

Are the currents highly variable between different manufacturers, within the same rail, or would most 550W PSU's have the same Voltage/Amp ratio on, say the 12V?

For those of you sith a high-end SLI setup, like dual 7800's, what kind of PSU are you using? I've never seen any advertized above 600W.

[werty316]

Usually with the 3v, 5v and 12v rails a 10% or 5%+/- ratio is used but I can't remember if it is 5% or 10%; anyhow having a massive +500W PSU isn't really what you need. Quality is number one always when choosing a PSU. No POS.
Random boots and PC shut downs are good indicators a PSU that doesn't provide not enough juice. Generally more amps is better. voltage x Current = Watts.


12v rail covers HDs, cdroms, fans etc.
3.3v rail covers CPU I think.
5v rail covers ram PCI slots I think.

As for voltage displays. They are for the bling factor. I have a Coolermaster RealPower550W that comes with the wattage display but I don't use it.

For SLI around 40Amps or more is good.

[Bio-Hazard]

Go here: http://www.extreme.outervision.com/index.jsp and use the program to figure out what type of PSU you really need. It's a pretty handy program. Quality is better than quanty in most cases, but you don't want to be under powered either.

[Null]

Go here: http://www.extreme.outervision.com/index.jsp and use the program to figure out what type of PSU you really need.

Nifty little configurator there.

301 watts.

Not so bad.

I got some room to spare.

Vroom! Vroom little PC Power & Cooling Turbo Cool 510 SLI psu.

You have performed flawlessly in my testing.

Too bad I don't have a pocket protector or a Radio Shack voltmeter. :wink:

[Frank Marino]

Go here: http://www.extreme.outervision.com/index.jsp and use the program to figure out what type of PSU you really need. It's a pretty handy program. Quality is better than quanty in most cases, but you don't want to be under powered either.

Thanks for this, apparently, I only use about 235W at 80%. I'm assuming that you want to make sure that you can power your pc to 100% though, right?

[Bio-Hazard]

Yup, that program is supposed to figure the max power your system will draw based on your input. If you OC or plan to OC your CPU or video card, make sure that you into that data also. OC'ing the CPU dramaticly increasesthe power draw on the PSU.

[Null]

I'm assuming that you want to make sure that you can power your pc to 100% though, right?

Roger that. You want to stress that puppy out to see what it requires under extreme conditions.

[PUTALE]

remember the program only calculate the max power wattage. It didn't really break down into each individual rails (BTW, rails are 12v, 5v, 3v). Personally, I tihnk a good stable PC should have at least 25amp on the 12v when using a goog high end graphic card. If SLI, you should look into like 30amp or more. And I think at least 400W is minimum.

[Frank Marino]

Thanks guys. According to that program and your advice on Amperage, I could go SLI with a 6600GT, or even do one 7800 before I need a new PSU.

I apreciate the help and advice.

[Bio-Hazard]

If I remembr right, to run a ATI CrorrFire system with 1900 series card, they recomemnded something like 34 amps total minimum on the 12v rails. That makes for a pretty healthy PSU. I know a friend of mine fried a OCZ 620 when reviewing a CrossFire rig, the PSU only had 33 amp 12v total and he was also running a FX60 CPU, so it totally over loaded the PSU.

[pym]

If I remembr right, to run a ATI CrorrFire system with 1900 series card, they recomemnded something like 34 amps total minimum on the 12v rails. That makes for a pretty healthy PSU. I know a friend of mine fried a OCZ 620 when reviewing a CrossFire rig, the PSU only had 33 amp 12v total and he was also running a FX60 CPU, so it totally over loaded the PSU.

Soon, we'll have to drag a power station behind our back just to meet the rapidly increasing power requirements. ;)
They'll have to find a solution for that problem...
There were times that 1KW PSU was a lot ;)

[werty316]

The day gaming computers to use massive 1000W PSU would be an bid eye opener. It really shows how computer power consumption has grown.