Am Montag, 30. Juli 2012, 10:08:24 schrieb Michael Mol: > On Mon, Jul 30, 2012 at 2:16 AM, Nikos Chantziaras <rea...@gmail.com> wrote: > > On 30/07/12 07:28, Michael Mol wrote: > >> On Sun, Jul 29, 2012 at 11:55 PM, Nikos Chantziaras <rea...@gmail.com> > >> > >> wrote: > >>> On 30/07/12 06:08, Michael Mol wrote: > >>>> On Sun, Jul 29, 2012 at 10:50 PM, Nikos Chantziaras <rea...@gmail.com> > >>>> > >>>> wrote: > >>>>> On 30/07/12 05:23, Philip Webb wrote: > >>>>>> i5-2550K & FX-4100 both use 95 W > >>>>>> (some of the more costly AMDs use 125 W ). > >>>>> > >>>>> Note that power savings are not important if you're not using a > >>>>> laptop. > >>>>> CPU > >>>>> power savings on a desktop don't translate to any relevant amount of > >>>>> money > >>>>> on your electricity bills. This is because neither of those CPUs > >>>>> really > >>>>> use > >>>>> 95W. That's just the thermal upper limit. > >>>> > >>>> To be fair, power savings are relevant if you're concerned about your > >>>> electric bill, or if you're concerned about heat management in your > >>>> system. > >>>> > >>>> Consider my dual E5345...leaving that on 24x7 appears to cost me about > >>>> 90USD/mo. > >>> > >>> CPU power savings will transform that into a 89.9USD/mo ;-) That's what > >>> I > >>> mean. It's not worth much. It helps quite a bit with laptop battery > >>> life. > >>> But for desktops, it doesn't do anything too useful. > >> > >> If you really want the hard numbers, check out some place like Tom's > >> Hardware or Phoronix. I forget which does the power consumption > >> measurements. At some of the hardware review blogs, you can get > >> numbers on idle vs full-load power consumption, as measured at the > >> wall. The difference truly is striking. > > > > When you have full load, the CPU won't clock down. So nothing saved > > there. > > When you're considering full load, the TDP becomes a useful estimation > of relative power consumption between different processors. > > > If you don't have full load, the clock-down doesn't save much compared to > > max clocks while idle. > > This is where you're wrong. > > http://www.tomshardware.com/reviews/ivy-bridge-benchmark-core-i7-3770k,3181- > 23.html > > http://www.tomshardware.com/reviews/fx-power-consumption-efficiency,3060-11. > html
I wouldn't trust anything Tom's publishes. That said, Intel's 'TDP' is not really a 'TDP' - for almost a decade Intel's 'TDP' is not the 'real' TDP but a 'usually you won't get higher than this' - until you run some really heavy stuff. Like compiling openoffice... AMD followed suit some time ago. So both numbers are misleading at best. That said, idle&low load consumption is fine with all CPU's. Mobos and PSUs influence that numbers a lot more. -- #163933
