Notebook vs PC Power Consumption

In my area, they are upping the prices of energy, so I'm becoming more energy efficient. I'm switching to purely lcds, I may replace my pentium d with something else, and I'm wondering...

How much power do laptops take over desktops?

I have always loved desktops, to take them apart, put them together, etc. But a laptop IS pretty.

And if it is energy efficient, then I'll go for it.

So how much power does a laptop use over a desktop? Is it like a lcd over a crt, I mean, if I got a laptop with similiar specs, would I notice a huge decrease in power usage?

Which laptop chips are also the best at energy effiency, and power? I'm guessing if I want to leave it on 24/7 I should steer clear of a pentium m/celeron m and go more toward a core duo/core 2 duo, or one of the newer amds?

If so, I may replace some of my aging systems with laptops. Not my best systems, mind you, but a few of them.

Thanks for your time.

 

To put it in a rather simplistic way, most laptops run on 65-90W power supplies. Contemporary desktops are using ballpark 350-500W power supplies. The difference in just that one aspect is huge.

 

They use significantly less power, but you can also be more conscious of your usage, make sure you turn the computer off, or set it with lower power settings, turn down your video card. The other thing to consider is that you spend lots of money buying a new laptop, doesn't that defeat the purpose?

 

Okay...

Would I need a laptop cooler for every laptop if I'm gonna run it 24/7?

Or is a laptop cooler simply for desktop replacements?

 

Not really. I spend like $200-$250 (big house) on power, and it's going up, if I were to cut power spending signifigantly, and buy a cheap laptop and use it for a year or two, I'd end up saving quite a bit of money.

Sometimes you gotta spend money to save.

Also, another thing is, turning off your pc gives it a surge every time. It's better for the life of the pc to keep it on. Also, that surge (To turn it on and off) sends more power too.

It's kind of like russian roulette.

It's better to keep it on, it uses a tad more power, but it prolongs the life of the pc. I'm deciding on keeping the pc on, but going for more energy effiencient pcs that'll last a long time.

 

This is perhaps the best way to explain the differences in power demands.

 

Thanks guys, but one other question...

If they run on 65-90w psu's, what is their REAL wattage? I mean, most desktops run on 350-500 watt psu's, but never use all of it's wattage...

So what is the average real usage of a desktop versus a laptop?

I'm assuming it's alot lower for both, but I'd like to know so I can make some calculations.

 

I've had desktop replacement laptops and have never used a cooler. Just keep the vents accessible to open air and keep the dust out.

All laptops have power saving features, which can be adjusted yourself. Most support cpu throttling drivers (aside from Celeron) that adjust proccessor speed to usage, which saves energy (IE; SpeedStep, PowerNow).

 

laptops converve MUCH less than desktop, using mobile meter (search in google) and run while using battery will show you exactly how much the laptop uses. I find the program is accurate since if your battery is 40whr(watts per hour) capacity, and your laptop can run max 2 hours, means your computer is using 20 whr.

and wi-fi, brightness setting or lcd turn off does conserve more energy. Mainly Pent M and core duo uses almost same power with core duo a little bit more. But celeron will use more power as those don't have speedsteps technology so can't run lower cock setting for saving energy.

 

WOW. I just did a check at Intels site.

A e6300 runs at 65 watts, and a t5600 runs at only 25 watts!

That is quite amazing.

Does anyone have any specs for video cards?

I'm not planning on gaming on these laptops, but if I got a replacement for the 1800+, maybe a 6150 if I could find one with a core 2 duo (knock on wood), maybe it will have super low power usage compared to the 6200le I use now...

 

there are more specs that use power than just cpu, like hard drive, and motherboards. The actual average or lowest energy I have seen in a laptop at idle, lowest setting like brightness and clock, is about 9 watts

 

Right right, but I was just noticing how much of a difference the wattage was in the the desktop and the notebook cpu.

Surely the rest of the components are also as big a difference...

 

ummmm...just how much power do you think your desktop consumes each month? Or more to the point how much does your desktop cost you each month...my guess is if left full blast running 24/7 it will be no more then $10/mo. Let's go wild and say it costs 4x that...or $40/mo. Even if your laptop costs you $30 less at $10/mo you are saving at most $360/yr. You would need the laptop to last about 6 years to break even.

Your home PC does not use much energy...if you have a CRT display those are pigs but not the system itself. And just because it has a 500w power supply does not mean it's using that much power all the time.

You are stepping over dollars to pick up pennies here...you would be better served to replace the 'fridge as most communities have special deals if you replace an older one with a newer more efficient model. Meaning they will either give you cash toward a new one or a monthly credit...WATCH LESS TV they are a huge power drain in a home...there are also programs to get your furnace replaced if it is old and inefficent either through tax/rate breaks or outright cash credits at the point of purchase.

Also even if your electric is the highest in the US you still you need to address the real power sink-holes in your home long before the computer is a real issue.

 

Heh... Well that's actually what I plan on replacing...

Not systems that have lcds. But the athlon 1800+ at it's two crts, ugh.

Like I said above, I have three crts on it. It's something I kinda must use, and the **** crts are using like 600+ watts. If I were to get something very energy effiecient, It would not put so much of a burden on the power costs.

The costs of getting three lcds to replace the three crts would equal the laptop and then some, so why not?

 

oh...yeah now I get it...replacing the CRT's with LCD's is a GREAT idea. I got it that ya wanted to replace your PC's with laptops to save money...hehehehe...oops!!

I was really aware of it because I just went through an bit the bullet replacing all the appliances and furnace the past few months. After the rebates and such it was a nice deal really.

 

Exactly, worrying about monitors and especially the pcs themselves is the last thing to do unless already replacing them anyway.
I have a large older home, spending about 2400 last fall has cut my utilities by about 65 bucks a month(from ~280 to ~220).
Keep in mind that monitors are not 24 hr a day things either, have them power down instead of screen saver.

also btw- yeah yeah in theory there is a spike and what not blah blah....turn the pc off when not in use unless it is a server. The power spike is practically non-existant (ALL pcs operate soft-on so damage is an urban legend) and as far as power use the spike in power usage is overcome by no more than 3-5 minutes run time. (yes I got curious and checked - idle current on my comp is .24A and during ~20 second boot seq it jumps to .8A)

EDIT: HOLY COW, just checked while running a benchmark. Almost 2 amps (1.92A) under high load. If you really want to save money stop playing games on your comp
also - readings were taken with a clamp-on upstream of the power supply so I make no claims to thier accuracy just to the relative readings I received.

 

Check the sig.

 

I've got a desktop with undervolted ATI Athlon 3200+ CPU and ATI integrated graphics which normally draws 60W at the mains socket which is plugged into a 17" LCD monitor which uses another 40W. So only 100W under light use but that is still 3 x more than my bigger notebook needs under light use and 5 x more than the smaller notebook uses.

John

 

well of course desktops will consume more power.

they are more powerful...

if you compare e6300 with the t5600, the e6300 has a much higher fsb

high end OCed desktop rams at pc 9200 can generate a lot of heat = power usage, whereas in laptops, they're all just pc 5300

basically every component in a desktop is more powerful to its notebook equivalent so i'd expect it to draw more power.

 

One thing to keep in mind is that the wattage is for maximum power usage. Most of the time the processor draws much less power. Since an e6300 is capable of SpeedStep just like the mobile processors, at system idle it'll probably consume roughly the same amount of power as a t5600. It's only when you're playing games or doing other processor-intensive tasks that it jumps up to 65 watts.

 

Those figures are not a representaton of power consumption, but TDP. Thats the "maximum" heat output of the processor, so actually, it can be more or less, depending on what the processor is doing. Intel hasn't been quite honest with its TDP measurements, and they are a little higher than those that have been published.

 

ok a laptop uses far less than most have stated here. They will draw close to 60W when charging the battery, but if you remove your battery and run off the AC power you're looking somewhere between 15W and 40W depending on your setup. However do remember that the notebook AC adapter is not 100% efficient and does get warm itself, so add a least an extra 15% to that figure.

As for desktop PC, it ranges from 150W all the way up.... all depends if you're overclocking etc, and have many GPU's you have etc.... do some googling, there are a few web pages which allow you to select your components and it will give you a good idea of how much current your PC draws.


Insane

 

So what is really the answer and what do you think?
Which one uses more electricity? I think that maybe laptops use less. Because you charge and use it etc.

 

If you're asking whether notebooks use less power than desktops, the answer is yes. By definition notebooks have to consume less power to be viable as a portable device, that's why mobile processor and graphics platforms are designed -- to compromise power consumption with performance. When it comes to desktops, power consumption takes a bit of a back seat to just having more performance.

The screen on a notebook is the biggest power drain, next would be the processor. Since you use a bigger screen with a desktop system and less power efficient and faster processor, you end up consuming a lot more power.

 

The majority of notebooks have a 90W PSU, but under light load a notebook may draw around 30W from the mains power socket. The current CPUs draw a maximum of about 25W under load so 90W overall power will need a very powerful GPU and all the peripherals under load.

In comparison a desktop computer may draw 100W under light load (excluding the display). The recent desktop CPUs include some form of speed / power control but some can draw up to 100W under load while the upper end GPUs need even more power. If my memory is correct, a 17" desktop LCD display needs about 40W. CRT displays use more power.

In summary, a laptop typically uses 1/2 to 1/4 of the power of a desktop computer.

John

 

it's obvious that notebooks especially those ULV models draw less power than an ordinary PC.

what the point of asking this????

just for the sake of asking???LOL

 

There are quite a lot of people who fail to notice the obvious in this world. It is our duty to help them and make our world a better place for us all.

 

At normal jobs, laptop consumes up to 25watts but when it comes to PC's it starts from 100watts.

 

I am asking this just out of curiosity dude. Considering your laptop charges and then you use the battery. I thought it used less power, and i searched the net and found nothing. So, i decided to ask here.

 

Yeah, laptops tend to fall in the 10-30W range. A desktop may hit several hundred watts.

(Do the math. The biggest laptop batteries can store around 90Wh, so if the system consumed 90 watts, it'd be able to run for one hour.

Now compare to a desktop, which may require a 400W power supply to even boot safely. Of course a 400W PSU doesn't deliver the full 400W usually (and it's only at boot that the PC uses full power on all components. Soon after, everything goes into a low power mode, and after that, only a few parts at a time will run at full speed), but it gives you an idea of the difference.

 

ok one intelligent question, My laptop have 65Watts adapter, i was wondering if my laptop is in sleep mode, using 30watts electricity or say its disconnected but if 65Watts adapter is plugged into socket, is it still Consuming 65Watts power? I guess yes, but just wants to confirm anyway.

 

also last year i think i saved about $50 in electricity bills because my laptop is always ON (except while I am moving from home to office and vise versa).

 

Actual power consumption is related to but not the same as the power supply rating. Notebooks use much less power but don't think that they only use 'such and such' because that is the size of thier power supply. Power supplies are not very efficient. Most Desktop power supplies are 65% to 75%. The vast majority of notebook power supplies are switching instead of linear and hit in the 70% to 80% range. There are high efficiency units of both types but they are more expensive. Since power is a greater issue for notebooks their power supplies have evloved a little more.

ie: A 90watt power supply in a notebook may pull 160 watts or more from supply when under heavy load. By the same token, when the notebook is only using 25W the power consumed by the system can be 40-45W.

Note that a dead battery being charged will greatly affect efficiency but a notebook will still consume less than a desktop.

I have seen several posts asking about power consumption ... here are a few things that will save you $$$$ on your electric bill.
1-number one, biggest savings here, first and foremost, Turn off the computer when not in use. Easy, right. Yep. However, I will bet ya someone argues with me. Setup standby and hibernate on the desktop also.
2-Get rid of the CRT, LCDs consume less power.
3-Use headphones/buds instead of that 600W surround system.
4-Turn off the monitor/don't use screen savers. You can't always shutdown when you leave for a bit. Save power on that CRT for 10 minutes and don't load up that processor and gpu with a crazy 3D screen saver.
5-make sure you have enough ram. Don't spin up that hard drive for swap files if you don't have to.
6-Underclock/Undervolt when possible. You dont need all of that 2GHz core2 when you are surfing for por...uh I mean researching a termpaper.
7-Last and least, you may see a minimal effect by shutting down services you don't need running.

 

I bought a Kill A Watt meter the other day and ran around measuring a few things in the house out of curiosity. For comparison:

P4 1.7, 200GB HDD, 512MB DDR, Radeon 9250, Codegen 350W PSU
~110W under light load

21" Sony CRT
~110W

Acer Laptop, Cel M 1.73, 80GB HDD, 14.1" LCD
~60W

68cm CRT television
~60W

Toaster
~800W! Good thing it's only ever on in short bursts!


I would have measured the fridge for comparison but didn't feel like dragging it out of its alcove to get at the power cord and power point.

 

800w! Wow....

 

Try an electric kettle. 230V kettles are usually rated at between 2 and 3kW but are only used for a few minutes.

John

 

http://www.getrichslowly.org/blog/2006/12/04/review-kill-a-watt-electricity-usage-monitor/

Nintendo Wii hits only 16w! That's pretty awesome. The microwave reigns supreme at 2k+w...and like the electric kettles, are used for only a few minutes.

 

My projector ... ~550W (based on ~4.5amp with a clampon)

 

Notebooks consume very little power unless it's a desktop replacement or those toasting P4's. My old IBM t41 consumed a meagre 8-12watts on battery. The laptop consumes most power during full load and charging at the same time.

 

Sure enough - 2400 watts. Makes sense I suppose, I vaguely recall it being mentioned back in school that water takes a lot of energy to change temperature.

Not quite an edit:
Ah google is my friend - water has a high specific heat index.

 

Hi Mayo,

Can you also check power consumption for DSL router, Cordless Phones, any surround sound systems?. My laptop is always connected to 2nd lcd monitor, 5.1 creative soundblaster speakers with 1 subwoofer and 2 speakers, extra keyboard + mouse, dsl router, external tv tuner and one more desktop + laptop is coming soon

 

We've had a large thread on this issue...I will soon merge them together.

The bottom line is that the power adapters for the largest notebooks are 120W while PSUs for desktop can be 500-1000W.

 

I sure can.

Linksys WRT54G wireless router
~5 watts regardless of load including trying out a test torrent

My old P.O.S. DSL-300 modem
~6 watts

Acer AL1715 17" LCD
~30 watts

El cheapo Binatone cordless phone
~2-3 watts on standby and while talking

I don't have surround but do have an old Logitech Soundman S-20 2.1 setup
~5-12 watts while playing music.

Lastly I was a little surprised at my old 51cm CRT TV, which I suspect is older than me (Rank Arena brand, wooden panels): 250 watts! I was expecting it to be less efficient than my newer 68cm but not by THAT much!

 

a lot of the big power supply stuff for desktops is hot air. No pun inteneded. If you arent running sli/crossfire and just have a ho-hum graphic card, 2 HDD and one optical, a 300W power supply is totally adequate. For a brief period the P4s needed absurd power, and generated absurd heat. So a 400W or better was de rigeur.
As far as saving $ on your power bill. Get some energy saver lights. Mine were literally $2 for a pack of 4 and give about 80 watts equivalent for 20 watts. replaced every light in the house and my bill went down about $25.
And yeah I switched form dual 19" CRTS to dual 17" LCDs last year. Much less juice, much less EMI in my guitar when I record.