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At the intel developer forum the CTO of intel called some Google engineer on stage to demand more efficient power supplies in PCs. The link says:Noting that the power supply is often the component that consumes the most energy in current PCs, Barroso highlighted findings from a newly published Google white paper (pdf).Now, this is absurd—the power supply delivers power but standing next to the power pigs at intel and blaming the power supply is a little like the pot calling the kettle black. Now the first thing needed from PC power is power factor correction like they have in Europe. Standard off-line power supplies draw a huge spike of current to top off the garbage-can capacitors right at the AC voltage peak. This makes the delivery and generation of the power far less efficient than if the current going into the supply was a sine wave just like the voltage. When those two sine waves do not lead or lag one another the power factor is a perfect 1.0.No wait, I still am mad about that crack from the Google “engineer”. I do think it would be great to have 90% efficient power supplies and I am pretty sure we already do—just look at some of the fan-less supplies already out. It is just so stupid to say that something delivering power is also consuming it. No, I think that motherboard is the highest consuming component in the computer, dude. That’s why I have a fan on the processor, the Southbridge and my nVidia graphics card.OK, back to PFC. I remember Linear Tech getting into PFC chips and when I was down at ON Semi last week I was pleasantly surprised to see they have turned their manufacturing might to the problem. Fairchild (pdf) makes PFC modules and never forget the Unitrode (pdf) division of Texas Instruments. And how about those wonderful folks at International Rectifier that poached our previous analog editor Joshua Israelsohn as well as Power Factor 1.Heck the hot-shots at Vicor already have a PFC supply ready to go. You will note the power efficiency is still only 75% because the PFC causes it’s own hit to efficiency but it really is a net gain since the transmission lines and generators can be reduced in size. Calling for efficiency without PFC is irresponsible. The next time those power hogs and intel call somebody up on stage it should be someone from Vicor or Lambda (pdf). I will listen to those folks when it comes to power supplies. The Google guys can crawl back to their stylish cubes and go back to typing, their primary skill. But they should stick to code, not white papers.Oh great balls of fire I just read all the way through that white paper—it is worse then just calling for the use of FETs and synchronous switching—they want to take the +5 the –5 and the –12 voltages out of the supply. Now I am really ticked off. Yeah, and lets turn off half the Google servers, that will save a lot of power too. Guys, please don’t mess with world standards. There are so few of them as it is. And it will be very nice to have the –12 supply to bias something or make a class D audio amp or something else that hasn’t been invented yet. This is what passes for engineering at Google? Good thing we can’t see software work. We would all die laughing.
