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A cooler CPU and mobo vs. burning those fans to the max ????

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September 5, 2006 7:50:08 PM

I've installed an extra fan into my P180B that I had, and I now have 4 120mm fans running at max. Noise doesnt matter to me - the PC is no where near my bedroom. It's actually not too noisy, but defiantely not quiet. What I am more concerned about is energy efficiency and wastage.

Does anyone know how much in $$ does 4 fans running at full cost you over 31 days X 24 hours ??? What's better - cool CPU and mobos or saving money on bills.

Does keeping your components cool prolong the life of the PC???

My CPU and mobo idle around 38/39 respectively. The peak around 44. I think that's pretty damn good on just air cooling. I love the P180.

Let me know. THANKS GUYS!
September 5, 2006 8:13:48 PM

Running 4 120mm fans will use up around 20-36 watts. I don't think that would kill your electric bill. Its prolly better to take wattage as to what your total system uses, then just 4 fans.

One bad thing with running 4 120mm fans or any system perhaps at full speed 24/7 is the amount of dust that may build up in the case fans or filters.

I really don't think systems that are properly cooled would have enough heat to really damage or reduce the life of any component.

Only perhaps pushing a particular component past its limits voltage wise will reduce its life or just kill it.
September 5, 2006 8:35:41 PM

When you say 20-36 watts, do you mean / hour or / what? Not sure about metrics - noob at that. What does a watt cost you? If you run them 31 days a month, 24 hours a day, what does that come out to? (I'll do the math - just need to understand the watts/unit situation).

Based on that then, should I switch off some fans and take it up to around 50 degrees for the mobo and CPU vs 40 now? Does it even make any difference?

I just dont know what effect 10 degrees or any heat for that matter has on components.

THANKS!
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September 5, 2006 8:53:09 PM

If you want to save some bucks and extend the life of your PC and its components, then turn it off when you're not using it.

If you must leave the PC on 24/7, then extra fans aren't going to make a big difference cost wise.

Cheerio!
A
September 5, 2006 9:38:53 PM

Quote:
When you say 20-36 watts, do you mean / hour or / what? Not sure about metrics - noob at that. What does a watt cost you? If you run them 31 days a month, 24 hours a day, what does that come out to? (I'll do the math - just need to understand the watts/unit situation).

Based on that then, should I switch off some fans and take it up to around 50 degrees for the mobo and CPU vs 40 now? Does it even make any difference?

I just dont know what effect 10 degrees or any heat for that matter has on components.

THANKS!


20-36 watts directly when you turn it on. In 50 hours usage would be around 1kw used.

I agree if your not going to use it, its better in my opinion to shut it off.

But if you want to try to figure out how much power your PC is using:

eXtreme PSU Calculator v1.3

or

P3 International P4400 Kill A Watt

And then figure out what your power company charges.
September 5, 2006 10:13:40 PM

Quote:

20-36 watts directly when you turn it on. In 50 hours usage would be around 1kw used.




A fan uses about 2-3W max. 12v * 0.18A = 2.16W and this is a high speed 80mm fan.

Thats nothing compared to other components your whole PC is probably using about 80-100W while its idling and about 150-200W when it's at full load (all depends on components).
September 5, 2006 10:20:03 PM

Well, I was taking measurements from that cacluator page.

It starts off with 43w, and then I minus that from what you choose componet wise, for example a normal 120mm fan is 5 watts x 4 20 watts.

Unless that is tottaly off I appolgise if I was being incorrect.
September 5, 2006 10:32:05 PM

yup you are probably right I didnt see those were 120mm fans. Probably around 5W (depends on speed), could be even less.

Try and read at what Amperage they work something like 0.18A or 0.25A.

20W is really not that much. You shouldnt worry.
September 5, 2006 10:50:32 PM

Yes, 20watts isn't much. Just trying to help the guy understand (fan wise) how much it takes to actually use 1 kilowatt in time. It should be around 50 hours to use up around 1 kwatt, and electric companies charge per hour(6-10 cents kwatt an hour?).

So, its really best to take the total amout the PC uses to really get an idea of how much you could possible save by turning it off vs leaving it on 24/7.

To me, dust is a concern. Heh, I hate dust. :lol: 
a c 478 à CPUs
September 5, 2006 11:46:08 PM

Assuming you are running the 120mm fans at full speed, each one will probably use 6 to 7 watts per hour. Measely.

If you are really concerned about power consumption then you should look at the other components in your system:

GPU - ATI cards are generally more power hungry than their nVidia counterparts. For example:



Then of course there is the CPU:



However, there is one component that many people overlook that can have a huge impact on how much power your PC will consume. That component is the Power Supply.

Power Supply - As everyone knows, the PSU draws power from AC outlet and provides it to the rest of the PC. However, it's not that simple. Power supplies have maximum efficiency ratings between 65% and 85% depending on the PSU. Generally speaking, more expensive PSUs will have greater efficiency than a cheaper model, but you'll need to read the specs to find out how efficient it is.

So what the hell is efficiency, and what's the difference between 65% and 85%? Efficiency determines how much (or little) watts is wasted as heat when the PSU converts AC power to DC power. For example, let's say your PC consumes 250w of power. A 65% efficient PSU will deliver 250w and consume 384.6w (250 / 0.65) of power. That means 134.6w is wasted as heat. An 85% efficient PSU will deliver 250w and consume 294.1w (250 / 0.85) of power. Therefore, it only wastes 44.1w. That's a difference of 90.5w. However, this is a very simple explanantion because a PSU delivering 20w to 400w or higher will not be 85% efficient throughout the power curve.

A more complex view also looks at how high the load placed on the PSU is. Let's take the 250w load from the above example and use that in a 350w PSU and 600w PSU, both of which are up to 85% efficient and have the following specs:


Load %...........................................Efficiency

1 - 40.........................................................50%
41 - 50.......................................................60%
51 - 65.......................................................70%
66 - 75.......................................................80%
76 - 85.......................................................85%
85 - 95.......................................................83%
96 - 100.....................................................78%

350w PSU - The 250w load on the 350w PSU is 71.4% (250w / 350w) based on the load the PSU will be 80%. That means the PSU will be drawing 312.5w (250w / 0.80) from the AC outlet to provide 250w to the PC. 62.5w is wasted.

600w PSU - The 250w load on the 600w PSU is 41.6% (250w / 600w) based on the load the PSU will be 60%. That means the PSU will be drawing 416.7w (250w / 0.60) from the AC outlet to provide 250w to the PC. 166.7w is wasted.

The example above illustrates that going overboard on a very powerful PSU for a PC with a very small load can cost you extra money on your electricity bill.
September 6, 2006 1:30:09 PM

Hey man! You guys know your stuff. But if you are looking at 10c a kilowatt hour, my word, thats really not a lot of money. If I understand this correctly - I have a 550W PSU, 50 hours = 1 KW. Takes my PSU about 100 hours to burn 1 KW (for simplicity). 31 days * 24 hours = 744 hours in a month. Therefore one average (and very simplistic), my PSU burns 8KW a month? Around a $1 ???? Am I totally missing the point here, cause that's really not a lot. Who cares about fans then. Please advise. THANKS!
September 6, 2006 2:09:27 PM

yes, you are missing the point...

let's just say you have a system that consumes 250W total.
In 1 month that makes 250W*24h*31=186000Wh -->186kWh

and if 1kWh is 10cents then its 18,60$/month
September 6, 2006 2:46:16 PM

Ahhhh, so a Watt is calculated per hour. Well that changes the whole picture. Geeeeezzzzz. $200+ a year. Glad I got the NeoHe 550. Hopefully it saves me a few pennies! Worth it to turn it off. Thanks for the help. I dont care about the fans anymore. Just got the turn it off when I'm not using it.
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