Will a 330W PSU handle my setup?

[KurskKnyaz]

Sytem:
-Asus P4P800 Motherboard
-P4 3.0GHz
-2GB ram 2 sticks
-3 Seagate hard drives
-SATA DVD-RW
-Audigy 2 PCI
-M-Audio Audiophile 2496 PCI
-Linksys Wireless NIC PCI
-SATA Card PCI
-Radeon 9800XT 256MB AGP
-3 USB devices

Fans:
-2 case fans
-1 CPU fan
-1 stock video card fand
-2 Fans in the PSU

I have an Antec TruePower 330W thats about 5 years old. According to the PSU calculator on Antecs's page my current setup should require a PSU that is about 120W more than what I have. However, my system is rock solid. I will be upgrading my video card to an ATI Hd3850 512MB. The Antec PSU calculator is telling me that card would require only 10W more even though it is way more powerful.

my concerns:

1. My PSU can do 17 amps on the +12V rail, the PCIe version of the HD3850 requires 28 amps. AFAIK if amperage is insufficient voltage will increase. Will this destroy my new video card, PSU, both, or neither.

2. How accurate is that PSU calculator? It seems to me like a marketing tools that factors in the active and not the idle states of components. I will not be burning a DVD, dowloading files, and accessing all 3 hard drives at once. While playing COD4 and running some CPU stress test in the background.

How necessary is a 500W PSU for my system when the Dell workstation I got for this office is running a Core 2 Duo 1.8Ghz, 2 Gigs DDR2 (2 sticks), 1 SATA drive, 1 SATA DVD-RW, onboard video, and an onboard NIC with only a 120W PSU? I have some old HP P3 systems that only run on 90W PSUs

 

[Jhhnn]

In your position, I'd upgrade, simply because 5 year old power supplies are reaching end of life, and because newer hardware needs different power distribution across the rails than your older unit provides.

One of the better deals currently available on an upscale Seasonic manufactured unit-

http://www.newegg.com/Product/...x?Item=N82E16817371006

Antec rebates are slow, but they do come through...

 

[KurskKnyaz]

got the card today and the 330W is doing just fine. ROCK SOLID!

 

[mpilchfamily]

That may be the case for now but the PSU is now under a much heavier load then it has ever been. Chances are it will die very soon. When it does there is a very good chance it will take that nice new video card with it. You need to replace the PSU ASAP with a good quality 450W PSU. DO NOT RISK YOUR NICE NEW CARD WITH THAT OLD PSU!

 

[KurskKnyaz]

I have a 430Watt laying around but it is made by some company called @-power and can only do 16A on the +12V. My 330W Antec does 17A an the +12 rail. The 430W I was linked to does the same.

 

[HOOfan 1]

Originally posted by: KurskKnyaz
I have a 430Watt laying around but it is made by some company called @-power and can only do 16A on the +12V. My 330W Antec does 17A an the +12 rail. The 430W I was linked to does the same.

apparently your PSU has a single 12V rail rate at 17A...the 430W you were linked to has 2 12V rails at 17 Amps each, with a combined current of 30 Amps.

If you don't want to listen to the suggestions, that is fine, but why did you ask the question then?

 

[KurskKnyaz]

Originally posted by: HOOfan 1

Originally posted by: KurskKnyaz
I have a 430Watt laying around but it is made by some company called @-power and can only do 16A on the +12V. My 330W Antec does 17A an the +12 rail. The 430W I was linked to does the same.

apparently your PSU has a single 12V rail rate at 17A...the 430W you were linked to has 2 12V rails at 17 Amps each, with a combined current of 30 Amps.

If you don't want to listen to the suggestions, that is fine, but why did you ask the question then?

No, My PSU has 2 rails. I asked the question because I wanted to know how accurate is the information about PSU's and how much of it is marketing hype. When the box says "minimum 450W PSU" do they mean a quality PSU or do they write that to compensate for the fact that buyers may have ghetto PSUs that would need higher Wattage to compensate for their quality?

The questions I specifically asked were:

How accurate is that PSU calculator? It seems to me like a marketing tools that factors in the active and not the idle states of components. I will not be burning a DVD, dowloading files, and accessing all 3 hard drives at once. While playing COD4 and running some CPU stress test in the background.

How necessary is a 500W PSU for my system when the Dell workstation I got for this office is running a Core 2 Duo 1.8Ghz, 2 Gigs DDR2 (2 sticks), 1 SATA drive, 1 SATA DVD-RW, onboard video, and an onboard NIC with only a 120W PSU? I have some old HP P3 systems that only run on 90W PSUs

Those systems are tested for stability.

 

[Zap]

Originally posted by: KurskKnyaz
How accurate is that PSU calculator? It seems to me like a marketing tools that factors in the active and not the idle states of components.

It errs on the side of safety (and maybe sales? ). The thing is that it just calculates wattage without breaking it down into specific voltages. Let's say you have two 500W PSUs. One is an older model with huge 3.3v and 5v rails, but a weak 22A on the +12v rail, while the second is a newer model with a huge 35A on the +12v rail, but much weaker 3.3v and 5v rails. Can one say that all 500W power supplies can run the latest video cards on modern systems? Once under load, the first PSU will likely give out while the second one has power to spare. Even currently sold power supplies have varying rail ratings, plus of course quality comes into play.

The PSU calculators are probably "safe" for buying any average power supply. Sure, good quality ones which put out the right amount of power on the proper voltages will always do better than those calculators predict. Also, calculating based on "worst case" scenarios is the "best case" because you know someone out there will just happen to load their systems in a way that everything in it hits peak power draw around the same time.

The other thing is that while a power supply is "rated" for a particular output, it may not be, uh, "healthy" for it to put out 100% of that power 24/7. People all have their own comfort level with power supplies. One person may be comfortable with a peak draw of 80% theoretical output, while the next person is only comfortable running with a peak draw of 50% theoretical output. This is something you have to decide for yourself, as the only "rule of thumb" is to not drive your PSU at 100% all the time. Do you aim for 50%? 80%? You choose.

Regarding a 120W Dell, well, Dell knows that the system will only have those parts, so it can just spec the cheapest (lowest wattage) unit available. The system I built for my mom three months ago only had a 220W PSU (made by Enhance) but that was more than sufficient for a basic home office system using integrated graphics. I measured power draw (using a Seasonic Power Angel, accurate or not) at around 60W idle.

 

[beray]

Originally posted by: KurskKnyaz

How necessary is a 500W PSU for my system when the Dell workstation I got for this office is running a Core 2 Duo 1.8Ghz, 2 Gigs DDR2 (2 sticks), 1 SATA drive, 1 SATA DVD-RW, onboard video, and an onboard NIC with only a 120W PSU?

I'd have used 150W PSU which allowed for flexible sourcing component variations. DELL's engineers would have much tighter source component control, allowing more precise lower power rating which reduced manufacturing cost and increased profit margin.

If your calculated power required is 400W, it is normally cheaper for you to buy 400W PSU than 500W PSU.

I have some old HP P3 systems that only run on 90W PSUs

Those systems are tested for stability.

P3s are ~30W class processors --> http://www.intel80386.com/cpuheat.html.

 

[KurskKnyaz]

Thanks for your insight guys. Given that I have a 1 year warranty I'll take my chances. According to the PSU calculator my prior Radeon 9800XT I uses only 10W less than my new HD3850. My system has ran rock solid for years. 10W more won't hurt.

 

[KurskKnyaz]

BTW I have this ridiculous tendency to push hardware to its max just to see how long it will survive. I still use an HP DeskJet 840C. I should just buy a Samsung laser because I only print in black and white and given the cost of ink the Samsung will very quickly pay for itself ($50 after MIR). ...but I've had the HP since 2001 and its still kicking. Its not perfect but pretty damb good for something with moving parts. Got me through high school and college.

I just found the receipt for that Antec TruePower 330W - It's 6th birthday was on May 15, so say happy belated birthday to my high-quality 6 year old PSU.

EDIT:

BTW I run a UPS so it is fed clean power. I guess thats the key to a healthy life. I live in a very old building in Brooklyn (it still uses a fuse box).

 

[HOOfan 1]

Originally posted by: KurskKnyaz


No, My PSU has 2 rails. .

your 330 Watt PSU certainly is not capable of 30 Amps on the 12V rail

 

[KurskKnyaz]

Originally posted by: HOOfan 1

Originally posted by: KurskKnyaz


No, My PSU has 2 rails. .

your 330 Watt PSU certainly is not capable of 30 Amps on the 12V rail

It does 17A and updated version of the TruePower 330 can do 22A. I think there is more to a PSU than numbers. Like I said I have a 430W @-power that does only 16A but I won't put any budget garbage into my system (also, with electrical output equipment, the heavier usually = better quality). My system is currently running rock-solid under load (COD 4). My PSU has overload protection so if it would be overloaded it would shut off. Not bad for a 6 year old PSU. If it dies on my a year from now my next PSU will definitely be an Antec.

EDIT:

Looking at the manual, I don't think it has more than 1 +12V rail. I remember when buying it that it had split rails but I think they meant the +12V, +3.3V and +5V are split as opposed to a regular PSU where they are...?

 

[HOOfan 1]

it also has Fuhjyyu capacitors that like to leak and explode

 

[KurskKnyaz]

If you think about it 17A x 12V = 204W. There's no way that an HD 3850 needs that much power. 28A x 12V = 336W so I guess those specs are put out to to compensate for poor PSUs. If this card ate 336W I would not be able to run it and that 450W PSU probably wouldn't save me.

Doesn't Seasonic make Antec PSUs?

 

[HOOfan 1]

Originally posted by: KurskKnyaz
If you think about it 17A x 12V = 204W. There's no way that an HD 3850 needs that much power. 28A x 12V = 336W so I guess those specs are put out to to compensate for poor PSUs. If this card ate 336W I would not be able to run it and that 450W PSU probably wouldn't save me.

Doesn't Seasonic make Antec PSUs?

not the originial Truepower...they were made by CWT.

Like I said, notorious for exploding capacitors.

 

[KurskKnyaz]

If it goes out I would rather have it go out with a bang. Think of it as a feature when your PSU lets you know its dead.

 

[HOOfan 1]

Originally posted by: KurskKnyaz
If it goes out I would rather have it go out with a bang. Think of it as a feature when your PSU lets you know its dead.

yeah and if it goes on the secondary side it may let you know that it is dead and so is your videocard, and motherboard and harddrives.

 

[KurskKnyaz]

This is physically possible and is known to happen?

Technically, a cap that explodes would have lost all the charge between its electrolytic plates and I don't see how it could generate a power surge to fry my components. I've heard of bad PSUs causing system instability and I can understand how insufficient amperage can cause an increase in voltage to compensate for power loss (the video card would probably lock up before this happens since over-volting a circuit would generate excessive heat). I've never heard of a PSU going out and taking hardware with it (besides, computer hardware has a lot of protective circuitry). The physics behind this don't add up. ...unless the explosion itself is pretty powerful. Maybe a month from now I should open up my PSU to see if any of my caps are pregnant.

 

[HOOfan 1]

Originally posted by: KurskKnyaz
This is physically possible and is known to happen?

If it blows on the secondary side, certainly it can and has happened

 

[tomoyo]

Uh psu's can and will destroy hardware. It's simple, feed the hardware too much or too little energy at the wrong voltages. I believe that's what happens when the secondary side of the psu fails. It's like shooting lightning into your hardware, do you really think your hardware would survive that way? Now to be honest, most psu failures will NOT kill hardware, but why risk it? Also why risk having hardware die 6 months from now due to slightly bad power...which can and will happen on marginal psus.

 

[pmv]

"I've never heard of a PSU going out and taking hardware with it"

I dunno, I think everyone on this thread is far more knowledgeable about this subject than I am, but for what its worth I submit the following anecdote. Previous PC but one, with cheapo-came-with-case psu, ran fine for a couple of years, then PSU just went dead. Went out to local electronic store and bought cheapest PSU of sufficient wattage available, machine resumed functioning. Few months later machine literally went 'bang' with a loud crack, smoke, and smell of burning plastic. Upon investigation turned out gfx card, dvd drive and either mobo or cpu or more probably both were kaput. Hard drive, fortunately was OK. Lord alone knows what happened but I never dared even put that psu in another machine to test it, chucked it out. Plus never again used cheapo POS PSU.

 

[KurskKnyaz]

Originally posted by: pmv
"I've never heard of a PSU going out and taking hardware with it"

I dunno, I think everyone on this thread is far more knowledgeable about this subject than I am, but for what its worth I submit the following anecdote. Previous PC but one, with cheapo-came-with-case psu, ran fine for a couple of years, then PSU just went dead. Went out to local electronic store and bought cheapest PSU of sufficient wattage available, machine resumed functioning. Few months later machine literally went 'bang' with a loud crack, smoke, and smell of burning plastic. Upon investigation turned out gfx card, dvd drive and either mobo or cpu or more probably both were kaput. Hard drive, fortunately was OK. Lord alone knows what happened but I never dared even put that psu in another machine to test it, chucked it out. Plus never again used cheapo POS PSU.

Kaput how? It sounds like a capacitor blew. If the capacitor explosion damaged your components then I would be careful, someone wants you dead. If the damage you are referring to is electrical damage then I guess I'm wrong when I say modern computers have a lot of protective circuitry.

My PSU is a good and has overload protection. If I was overloading it my system would power off. Apparently I'm not. 28A x (12V from PSU + 3V from AGP slot) = 420W. I don't see how this Radeon 3850 graphics card could use that much power.

 

[Zap]

Originally posted by: pmv
for what its worth I submit the following anecdote...

Thank you for sharing. Some people still don't believe, but hopefully they learn without having to experience it like you.

I'm not saying spend a fortune on the PSU, but just to avoid known "crappy" units.

 

[PlasmaBomb]

You could always use a multimeter or killawatt meter to measure how much juice you are pulling.

IMHO you are likely to be pulling over 200 W at full load. A 3.0 GHz Northwood is rated at 82W alone and a prescott is rated at 89W. A 3870 512 mb will pull a real 81W although it is rated at 105W, a 3750 512mb might pull 70W a 3750 256mb pulls ~60W

So a optimistic estimate would be 60W Processor + 70W GPU + 20W mobo + ram + 30W HDD + 30W PCI (max load) + 15W USB (max load) + 10W fans = 235W a less optimistic calc could see you up at ~270W