I stand corrected! The dual 12v rail did not come about because of a mandate from Intel engineering - but rather from the one of many asinine EU standards pushed out this decade:
http://www.overclock.net/faqs/88626-info-do-you-need-multiple-12v.html [snip] Why did multiple 12V rails come about? Multiple rails came about because the EU mandated that the power on a single rail should not exceed 240VA (12V x 20A). Intel then stipulated in the ATX12V v2.xx standard that if the power on a 12V rail was likely to exceed 240VA, a second 12V rail needed to be engineered. For practical purposes, a limit of 18A was used, allowing for 2A headroom. Manufacturers replied by mass-producing multiple rail power supplies, using several types of engineering. Some power supplies are well engineered, and the 12V rails are truly separated with separate transformers. However, others draw power from one single transformer and the rails are only separated after transforming takes place. The issue with multiple rails is that the power per rail is relatively low, which unfortunately often results in the use of inferior parts. [/snip] I think the EU is trying to compete with California on who can pass the most misguided, outright stupid energy regulations. What's next, banning diesel? :) > From: [EMAIL PROTECTED] > To: hardware@hardwaregroup.com > Subject: RE: [H] PC Power & Cooling S75QB 750W EPS12V Power Supply $149 free > shipping > Date: Fri, 9 May 2008 07:59:45 -0400 > > > Long ago Intel required dual 12v rails for power supplies in systems based on > that unmitigated disaster called "Prescott", the thought being that a > dedicated rail for CPU and another for peripherals would ensure clean power > and push manufacturers to beef up wattage. > > Forward to today where we now have GPUs that surpass power draw of most CPUs > and how any one component can surge in draw, Intel has backpeddled and now > sanctions (as per their online builders spec guide) the use of massive 12v > single rail power supplies because of how dynamic these draws can be. What > good is a dedicated 20A 12V rail when a GPU can have a peak of 25-30A? > > >> Date: Thu, 8 May 2008 20:26:18 -0700 >> From: [EMAIL PROTECTED] >> To: hardware@hardwaregroup.com >> Subject: Re: [H] PC Power & Cooling S75QB 750W EPS12V Power Supply $149 free >> shipping >> >> Is a single 60A 12V rail better than multiple 12V >> rails totaling ~60A? Too bad the >> Red version is not on sale also! >> >> Who makes the Silencer Quad for PCP&C? >> >> >> Al wrote: >>> >> http://www.newegg.com/Product/Product.aspx?Item=N82E16817703009 >> >>> $149 free shipping >>> >>> >> http://promotions.newegg.com/PS/041508/index.html?cm_sp=SubCat_PowerSupplies-_-PS041508-_- >>> >>> >>> Al >>> >>> >> >> >> ____________________________________________________________________________________ >> Be a better friend, newshound, and >> know-it-all with Yahoo! Mobile. Try it now. >> http://mobile.yahoo.com/;_ylt=Ahu06i62sR8HDtDypao8Wcj9tAcJ > > _________________________________________________________________ > With Windows Live for mobile, your contacts travel with you. > http://www.windowslive.com/mobile/overview.html?ocid=TXT_TAGLM_WL_Refresh_mobile_052008 _________________________________________________________________ Get Free (PRODUCT) RED™ Emoticons, Winks and Display Pics. http://joinred.spaces.live.com?ocid=TXT_HMTG_prodredemoticons_052008
