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WHY PSU?

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April 4, 2006 6:34:07 PM

Hello Guys,
Just a Little info. i need here, DOES PSU really BOOSTS the System performance if we got >=400 WATT PSUs as required by the MOBO Menufacturers? My Mobo requires min. 400 WATTS but I got 300 Watt PSU of .. yes Lite-on (ITS REALLY 300 WATT) and its working fine ( but i never compared my pc to anyone and oh i never overclock coz' i cant afford water cooling).

I got the Mobo of nonfamous but good FOXCONN-WinFAST NF4K8AC with A64 3K+ .. 1Gig RAM (Budget Corsair), X700PRO--256 Gig ddr3, 1 SATA-SPINPOINT of 120 Gig, 1 lazy IDE of 10 Gig (Very OLD), 1 DVD-RAM, 1 DVD-ROM (Both are of LG's) and BLA BLAH other dingy mingies like audigy-2 value... please Help OUT .. im asking abt the real >=400 watt giving PSUs ...

THANKS ALOT IN ADVANCE. . . .

More about : psu

a c 158 ) Power supply
April 4, 2006 7:04:01 PM

PSUs do not boost performance, but provide power. Sufficient clean power makes your system run stably. An PSU unable to provide sufficient power can cause system instability and abnormal wear to system components. This wear can lead early component failure. Most component mfrs put some "slop" room into their ratings. This slop is to account for the lowest common denominator PSU mfrs - it's better to have too much, than not enough.

If your system is running stable, even while running severe stress tests, then your PSU is probably sufficient. A simple way to check for an underpowered PSU is to remove the side of your system case and listen closely to the system while you put a CD or DVD into the drive. If any of your system fans decrease speed (listen closely) then your PSU is having a hard time with the load that is on it. If it passes that simple test, then monitor the voltages of the 3.3V, 5V and 12V rails while running a stress test. If the voltages remain within + or - 5% of the specified rating and do not fluctuate a lot, then your PSU is capable of handling that load. Would it be better to have some more "slop" room? It gives me a little comfort and that comfort is inexpensive considering a good Fortron 400W is only $40....but it's your money and you can spend it however you want to spend it.
April 4, 2006 7:04:28 PM

No, 2 otherwise identical PC's, one with a 400w and one with an 800w PSU will run benchmarks exactly the same (with some caveats).

Caveats:
The PSU has to be good enough to power the system.
A higher quality PSU will provide more stable power, allowing you to overclock the system further than one with less stable power.

Lite-on isn't a really good PSU mfg, but if 300w is running stable and not heating up the PSU, then its fine.

Mike.
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April 4, 2006 7:17:34 PM

Like the other two have said, PSUs don't boost performance by themselves but the more components you add to the system, the bigger the chance of instability. If your PSU is putting out a stable 300W then you can check (roughly) whether it can handle your system requirements by adding up the power requirements of each component.

Also, you don't need to water cool in order to OC, you just can't OC as much. I would think that the percentage of ppl who have water cooling out of all the ppl that OC is pretty small. For instance, I have my 2.4 running at 2.6 and my CPU temperature is at around 50C at load.
April 4, 2006 10:30:15 PM

LXGAMER:

Don"t get too comfortable with that powersupply. Bet it's blowing lots of very hot air and it's not coming from the A64! Overloaded PSUs get hot! The heat will eventually put components out of specification, compounding problems.

The mobo: when voltage gets low, like from an overloaded source, some circuits, especially voltage regulators tend to draw more current to compensate - MORE HEAT! Next, the capacitors around the regulators heat up (they take on a dome shape) then leak (white powder on top)--- throw your mobo away and if your PSU fails in a bad way, throw in a few other components.

If it sounds like I'm trying to scare you I am. you're 100Watts under Manuf. recommendations. It may look fine now, but it's like giving your machine a slow silent disease...

DON'T DO IT!

BTW, a good PSU will shut down when overloaded.
April 4, 2006 11:03:02 PM

THANKS ALOT ALL THE BUDDIES HERE ... I WILL SOON UPGRADE MY PSU to 400 Watt or maybe further .. ..
a c 158 ) Power supply
April 5, 2006 12:47:56 PM

As previously stated, I think it's a good idea to have more power than you need.

That being said and considering his specs, there is such a thing as going overboard and I think you laid it on a little thick.
Quote:
Bet it's blowing lots of very hot air and it's not coming from the A64! Overloaded PSUs get hot! The heat will eventually put components out of specification, compounding problems.

Here you make a big assumption: his case is not cool. He never stated what type of case or cooling inside of it. Also - we both know that the PSU does not exhaust into the case, but to the exterior of the case. Will a heavily loaded PSU be hotter than normal - YES. Can that heat cause it to provide bad voltages to the PC - YES. Can an overheated PSU raise the ambient temperature in a case - if the case is not well ventilated, then yes, but otherwise any temp raise would be nominal.

Quote:
when voltage gets low, like from an overloaded source, some circuits, especially voltage regulators tend to draw more current to compensate - MORE HEAT!

Agreed and one of the reasons I told him to check his voltages for fluctuation and to make sure they are within 5% of their rated voltages.

Based on his components, his max theoretical draw is around 250W and there is no way he's going to get all of his components to at max at one time. I'd be willing to bet that his average draw isn't more than 150-175W. Assuming 70% efficiency and 150-175W draw, he is not pulling more than his PSU is capable of providing. He still needs to do the simple testing that I suggested earlier to make sure that his system is safe to operate. I still think it is better to have too much power, but he isn't in dire straits if his PSU is passing those simple tests and running stably. JMHO... :wink:
April 5, 2006 1:46:21 PM

I had to add... if you are running on-board video, your 300 watt PSU is probably fine. If you are running an add-in card, especially if it's something more than a GEForce 6200 or low-end ATI card, upgrade!

I once had a bad power supply that tested perfectly fine in operation, but it must have been causing spikes from time to time, probably during power-up, causing it to fry one motherboard and TWO cpu's in twelve months before I figured out that it MUST be the power supply causing the trouble. Needless to say, it was some off-brand $35-40 power supply. Ever since then, I've been running Antec, and have not had any issues. My two cents: Don't buy a $40 power supply, and buy a good brand. Paying $80 for a good 450 watt PSU seems like a good buy when you know it's powering over $1000 of equipment.
a c 158 ) Power supply
April 5, 2006 3:18:35 PM

Per his first post, he is running an X700Pro.
Quote:
My two cents: Don't buy a $40 power supply, and buy a good brand.

We both agree that a PSU is one of the most critical parts of any rig. I just don't think you have to spend an arm and leg to buy a really good PSU. There is no doubt that Antec makes good PSUs. You rightfully pay for that quality from Antec, but that doesn't man that there aren't good PSUs out there for less money. The FSP that I linked is a great little PSU - especially at that price point. If you take a look at the top PSUs on the market right now, you will see that FSP/Fortron is producing top-notch PSUs.
April 5, 2006 6:16:44 PM

Hello Guys this is my first post here.
I've A64 3200+ winchester on MSI k8n Neo 4 Platinum mobo.
My power supply is 300 watts FSP-Group 300-60 btv(pf) I cant see the power ratings right now coz the sticker on PSU is on the other side & i've to open the PSU to see it. But I've attatched the image showing voltages and temps the software is everest. I think currently power supply is enough for my pc....requirements but I'm planning to buy GFX card. I've also attatched the screen shot of calculated power supply wattage required from this site http://www.jscustompcs.com/power_supply/
according to this site if I add geforce 6800 gt to my rig my total required watts are 259.
Is my power supply enough to handle gfx card...?

I've 2 extra fan one on back pannel blowing air out and one on front blowing air in. Temps are too high coz it's very hot here room temperature is around 37C to 40C.



sorry for my english :) 
Reguards.
April 5, 2006 7:20:30 PM

faizanahmad, even though your thread should have arguably been a new topic, I'll submit my answer here anyhow.

If you have a 300 watt power supply and your new video card is going to push your system close to that 300 watt limit, then yes, I would suggest that a new PSU is in order. Keep in mind that if you purposely buy one that has a MUCH larger limit, such as 500 or 550 watt, that doesn't mean that your computer will draw more power, it just means that the power supply will be better able to maintain a stable operating condition. With the heat factor you mention, getting that new video card, even if it doesn't make the total system wattage top 300, may still overheat and damage other parts.

To paraphrase: get the new PSU. You can always use it for your next system, and it will better handle the heat and additional load you plan for.
April 5, 2006 7:37:11 PM

It's a general rule to never load a PSU with more than about 75% of its rating. Less if its a cheap PSU.

So your current setup is fine - you're running about 70% load.

If you upgrade your video card that puts it at 86% load. While FSP power supplies are good, if it was my computer I would get a new PSU.

Mike.
April 5, 2006 7:38:12 PM

Also consider that it isn't just the total wattage that is important. What does the power supply output on the 12 volt rail(s)? What does it output at 5 and 3.3 volts? Your 300 watt power supply may have enough total wattage, but your computer may want more on one of the rails than the power supply can provide. It's easier just to make sure you have a good 100 watts extra.
a c 158 ) Power supply
April 6, 2006 12:26:42 PM

Link to FSP - the link to specs is at the top of the page under the second group; ATX 12V. 15A on the 12V rail. The 3.3V rail is reduced from the 5V rail, so there are some amperage constraints between those two rails. That being said, the 12V rail is beefy for a PSU only rated at 300W. I like the fan grill on the rear - will allow for easy, quiet airflow. Has good overvoltage protection...it looks like a good all-around PSU.
April 7, 2006 6:39:50 PM

thanks but my psu is without fan grill :(  and my psu is fsp300-60btv(pf) and this btv(pf) model is not listed there..
Thanks anyway.
April 8, 2006 3:57:29 AM

FSP 300 will likely power your rig, problem free.
a c 158 ) Power supply
April 14, 2006 12:03:48 PM

I agree with Crash on this PSU working. BTW, it's likely that the only difference between the FSP 300-60BTV and the 60BTV(PF) is PFC. If you live anywhere in Europe, then FSP had to add PFC to the PSU due to regulatory requirements. [/shrug]
April 14, 2006 3:57:11 PM

thanks, but
what you mean by Crash on this PSU working?
April 14, 2006 11:05:32 PM

forshortened nickname
!