Fx8120 Vs i5 2500k @1.4v [Electricity consumption]

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bartholomew

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I know that @ 1.4v, the fx 8120 would consume almost twice as much power as the i5 2500k :pfff:

What I would like to know is;
When it comes to my electricity bill, will I see a major difference between the two processors?



P.s. - I know the performance difference between the two :)
 
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The 8120 only consumes that much at load. Most of us don't use our CPU and GPU at 100% load 100% of the time. For example, my PC at home is currently on in case I need to log in from work and get/do something. It's idling however, so the amount of energy used is rather low. (i5 750 with speedstep turned on, and a 5750. Neither of these are big users of power.) My PC is turned on 24/7. When I get home for an hour or so I play some games, and most of my weekend (5-8hrs) is spent playing games with more time (3-5hrs) spent watching DVDs or hulu. I don't worry to much about it idling because an i5 750 with speedstep, 4GBs of ram, and a 5750 shouldn't use much more then a 60-75W light bulb. If you look at reviews and see 400W, don't...

jasont78

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amd would use more power 2500k could run upto 4ghz+ standard voltage i wont even put over 1.3 thru my 2500k no need still get 4.6 at that, if efficiency is your thing its a no brainer, intel!
 
if yoy know how many watts difference it is, then multiply watts, by number of hours in day, by number of days in year divide by 1000 and then multiply by unit cost of electricity.

Example 20W difference, x10 hours a day = 200 x 365 days = 73,000 / 1000 = 73 x 0.13 (estimated unit cost) = $9.50 or £9.50 depending on the unit cost currency.
 

4745454b

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Close monkey, but it can be way more involved then that.

Assuming you leave speedstep/cool n quiet enabled then you need to take idle speeds into consideration. Because the 2500k can finish a task faster and clock down faster, the actual savings will be higher then your math suggests. (unless this rig is dedicated to something that the 8120 can beat the 2500k in, in which case it will come out ahead.) See if you can't find one of those laptop reviews where they show this in action.
 
I am aware of those reviews, however the typical usage scenario for a PC is that it is doing stuff, and then left on (well mind are anyway), so even if it finished early it does not mean that it is going to be turned off.
I'm treating the 20W as being a 'working figure' just so that maths gives an answer, in reality it'll probably be about there on average or somewhat less. So the answer will be below $10/year in power if one PC uses 20W more than another PC on average. Of course platform wattage might have a bigger difference.
 
well heres my typical day my pc is on 16 hours a day every day. in that day the pc is at max load for about 2 hours the rest of the time its idle or close to...
so running at around 100w total 49w cpu 28w gfx 15w motherboard 10w fans at idle
130 cpu ,180 gfx 15w motherboard 15w fans 20w hdd totals 350w ish
my electric costs 16p p kw daytime and 9p per kw night time with most of my time being spent on the pc at night say 12 hours the rest on daytime tariff.
this has a typical impact on my bill of £32 per quarter on top of what i already use.
if i swap it out for an fx i would likely see an increase of £12 over a quarter so £48 per year...
if i swap out my i7 for an i5 2500k then i would save about £4 per quater or £16 a year.
i deliberately chose my configuration because of the impact it would have on my wallet. i would say that it has saved me around £100 so far this last 2 years...
in fact its actually costing less to run than my old amd 6000x2 88gt setup...
 

bartholomew

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well follow the sums I've shown you and use 200W difference, or just multiply the answer by 10. so maybe $8/month difference, depending on usage if at load 100% of time.

at idle the fx is better so if you assume that 20% of time you are loaded, 200*20% = 40W and 80% of the time you are not loaded -20W *80% =16W then the nett increase is +24 W, so about $12/year

The sums are not difficult, try it for yourself.
 

4745454b

Titan
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The 8120 only consumes that much at load. Most of us don't use our CPU and GPU at 100% load 100% of the time. For example, my PC at home is currently on in case I need to log in from work and get/do something. It's idling however, so the amount of energy used is rather low. (i5 750 with speedstep turned on, and a 5750. Neither of these are big users of power.) My PC is turned on 24/7. When I get home for an hour or so I play some games, and most of my weekend (5-8hrs) is spent playing games with more time (3-5hrs) spent watching DVDs or hulu. I don't worry to much about it idling because an i5 750 with speedstep, 4GBs of ram, and a 5750 shouldn't use much more then a 60-75W light bulb. If you look at reviews and see 400W, don't think it pulls that all the time. If you are like most people, it probably never gets that high.
 
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noob2222

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The biggest issue i see on the hard ocp review, whats thier voltage? 1.4, 1.5, 1.6?

bulldozer-overclocking-efficiency,F-M-316786-13.png

http://www.tomshardware.com/reviews/bulldozer-efficiency-overclock-undervolt,3083-18.html

Maximum pull during the test was 350 watts for 5-8 seconds, while most of the time is spent below 250 watts.
Toms used 1.5v for their 4.6 ghz oc ... imo thats friggin insane. looking at the chart above, their 4.0 ghz was at 1.38v, never peaked over 250W other than a split second at the end.

Overclocking BD doesn't require that much voltage unless you don't know what your doing, or want to prove that you can drain some power.

my overclock is 4.7 ghz at 1.366V on this asus board and i know im not the only one.
My friend has his at 4.5 ghz at 1.33v on his gigabyte board on the stock cooler.

As for your question, you might see $2-3 max per month over running an i7 2600k during gaming sessions if you pump the voltage up to 1.45v as most of the tests out there did. running at 1.36V, maybe not so much of a difference, but ~$1-2

I don't have a wall amp meter but i know for a fact that im not pulling nearly as much as the tests show.
 
well i do have a wall meter and like i said my bill went up by £30 a quarter. on the system as a whole... i dont see where your getting this 1-2 bux from for cpu only...
oh let me guess its them rose tinted glasses again... pfft.

get real... the fx is a juice monkey it costs more to run, end of story...
you can crow as much as you like but the facts are it uses more power that its competitors, its slower than its competitors on 99.99% of applications. so not only will it cost you more to run it will produce less at the end of it...
if you want to buy less and pay more than bigger fool you... if you want the best then other brands are where you need to look...
 

noob2222

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looking at your sig, and the hardocp article linked, the overclocked 920 draws 505W load and the 8150 draws 452W. not overclocked its 265 for the 920 and 258 for the 8150.

how is the 8150 going to increase your power consumption when it draws less power than the 920? who is wearing rose colored glasses?
 
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