...and I probably left 6 other things that change out, that was just what came to mind immediately. :-)
*Drew Van ZandtArtisan's Asylum Board of DirectorsFirefly Arts Collective Board of Directors* On Fri, Jun 19, 2015 at 2:51 PM, Joe Polcari <[email protected]> wrote: > And that’s why. Thanks. > > From: Drew Van Zandt <[email protected]> > Date: Friday, June 19, 2015 at 1:32 PM > To: "[email protected]" <[email protected]> > Cc: Richard Pieri <[email protected]>, "[email protected]" < > [email protected]> > Subject: Re: [Discuss] Cool Processing > > You're assuming changing the voltage changes nothing else, if you try to > apply Ohm's law directly. Many other things change when you change the > supply voltage of a semiconductor/PCB. > > Among them: > Switching thresholds > Edge rates > Leakage currents > Capacitance of most of your capacitors > > *Drew Van ZandtArtisan's Asylum Board of DirectorsFirefly Arts Collective > Board of Directors* > > On Fri, Jun 19, 2015 at 1:26 PM, Joe Polcari <[email protected]> wrote: > >> And ohm's law doesn't apply why? >> >> Sent from my iPhone >> >> > On Jun 19, 2015, at 1:23 PM, Richard Pieri <[email protected]> >> wrote: >> > >> >> On 6/19/2015 11:02 AM, Steve Litt wrote: >> >> Today I have a 16GB RAM box, with dual core CPU (I wanted things to >> >> stay cool), >> > >> > I think I recently mentioned buying a new notebook. If I didn't, well I >> am mentioning it now: a Mythlogic-branded Clevo P750ZM. It has a Core >> i7-4790K processor. You read that right: a 15" notebook with a socketed >> Devil's Canyon i7 desktop CPU. I think I have some grounds for saying that >> limiting yourself to 2 cores is a poor way of managing heat. >> > >> > AMD and Intel processors draw substantially more power than they >> actually need. Every processor is different and the minimum stable power >> varies so they ship with the stock power draw set high enough that all >> processors in a series will run stably. Excess power turns into waste heat. >> This is why my i7 quickly reaches 99C under load and throttles if I don't >> do something about it. >> > >> > That something is called undervolting. As the name suggests it means >> reducing the voltage that the processor draws. Since every processor is a >> little different there is no single ideal undervolting setting. Finding the >> ideal for a given processor requires some trial and error, same as >> overclocking. A common starting point for Haswell i7 processors is -80mV >> dynamic CPU voltage offset and -100mV processor cache voltage offset. My >> 4790K barely reaches 80C with Intel XTU's stress test with these settings. >> That's the same as the i7-4790S at 3.2GHz (what the notebook originally >> shipped with) while running 20% faster at 4.0GHz. I figured that was good >> enough and called it done. >> > >> > -- >> > Rich P. >> > _______________________________________________ >> > Discuss mailing list >> > [email protected] >> > http://lists.blu.org/mailman/listinfo/discuss >> _______________________________________________ >> Discuss mailing list >> [email protected] >> http://lists.blu.org/mailman/listinfo/discuss >> > > _______________________________________________ Discuss mailing list [email protected] http://lists.blu.org/mailman/listinfo/discuss
