Wednesday Oct 31, 2007

Blame storage

"Is storage becoming IT's Hummer?" asks The Register. Reporting from SNW Europe they report that as data centers reduce the power cost of computing, storage is poised to become the biggest energy consumer. Well that's just the outcome SNIA hopes to avoid with their Green Storage Initiative. The efficiency race between computing and storage is one where we can cheer for both sides. Besides, as Jonathan points out, the distinction between computers and storage is blurring fast.

The Reg says that virtualization will be primarily responsible for reducing computing power usage through consolidation. Certainly the most effective way to save energy is to follow your mother's command: "Turn that thing off if you're not using it!" But I think the Reg is a bit premature in giving the industry credit for solving the problems of computing power usage. Yes there's a lot of innovation in this area making data centers more efficient in many different ways. But there remains a lot of hard work to do by vendors and users alike.


Wednesday Oct 17, 2007

Green as in money

The Register has a cynical article on the newly formed SNIA Green Storage Initiative as "yet another eco-cause group."

"As par, the initiative includes vendors hoping to woo customers who a) want to cut energy costs and b) feel they owe nature a favor despite it providing terrors such as roving packs of wild dogs and brain eating parasites."

So the Reg thinks that green initiatives are meant to lure dumb customers into paying more for dubious benefits to Mother Earth. Well, I think that former Labor Secretary Robert Reich gave a much better characterization of company eco initiatives on NPR today. Sure companies are doing it to make money. As Reich commented on companies who proudly proclaim their energy saving programs that save millions of dollars, finding money saving efficiencies used to be called simply good management. Reich said you should not be surprised or impressed by eco claims, but should look at how it benefits you.

Sun has always been open about our eco initiatives being as much about green money as about green ecology. And as Reich noted, that's what makes it work, not vague notions of corporate responsibility. I like to think of Sun as a reponsible company, and I'm glad that our green initiatives make money for shareholders and save money for smart customers.

Thursday Oct 04, 2007

I'm unfair to HP

I measured electricity usage of our home computers using a cheap clamp-on ammeter from Radio Shack. I concluded that you need to make your own measurements because many of my preconceptions did not hold up to actual measurement. Since then I bought a more accurate and convenient Watts Up meter for $21 from, and re-measured everything.

    To my colleagues at HP: I apologize for saying your PC used 300 watts.

100 watts is more like it. I likewise overstated the power usage of other PC's. I correct the measurements here, along with some discoveries about Windows and Ubuntu power management. You may be asking, why should I believe you now? Good question. You should not believe some random person you find on the net. You should get your own meter and measure your own equipment.

Why might you halfway believe me, enough to read a bit more? Well, Watts Up does seem to be a more reliable instrument, and unlike my earlier measurements it corrects for the power factor. It displays the power factor, which can vary greatly from one device to another. As a check on the new meter I measured a 3-way light bulb: the 60w setting measured 44w, the 100w setting measured 89w, and the 150w setting measured 135w. At least I'm assured it's not measuring high.

A colleague in the SPEC power committee laughed at my new meter, “You mean you trust a Watts Up meter?” For the upcoming SPEC power benchmarks that team of engineers from many companies, universities, and agencies has written elaborate requirements for the power meter and measurement protocol to be sure that results tested by one lab will be comparable to results tested by another lab. But for home, if you can get any information at all about the power your electronic gear uses, that's good.

First I looked at how many watts they used in normal home, light load operation. I switched the Linux distro on PC2002 to Ubuntu 7.04 Feisty Fawn, and its power management software seems to be the equal of Windows.

OS Computer Monitor Speakers Total
PC1999 Linux 39 26 1 66
PC1999 Windows 98 37 26 1 64
PC2002 Linux JDS 95 34 - 129
PC2002 Windows XP 61 34 - 95
PC2002 Linux Ubuntu 57 34 - 91
PC2006 Solaris 77 22 - 99
PC2006 Windows XP 67 22 - 89

Next I looked at how many watts they used under a heavy load. These weren't identical controlled loads, and workload really matters to how much power is used.

OS Computer Monitor Speakers Total
PC1999 Linux 46 26 1 73
PC1999 Windows 98 55 26 1 82
PC2002 Linux JDS 95 34 - 129
PC2002 Windows XP 100 34 - 134
PC2002 Linux Ubuntu 118 34 - 152
PC2006 Solaris ? 22 - ?
PC2006 Windows 115 22 - 137

How much of difference does workload make? Here is the power consumption of PC2002 running Ubuntu:


Watts (PC only)

download OS updates


system quiescent


100-Base-T file copies

80 - 100

Play Supertux arcade game


Scanning document with USB scanner and xsane


Afterwards [Note 1]


Killed mysqld


[Note 1] I don't know what set off the MySQL daemon, whether it was doing useful work, or had just run wild. But without the power meter, had I noticed anything amiss at all, I would have just been puzzled that the fan was running. When I stopped the daemon, power usage fell back down to normal levels.

Next I suspended each PC by pressing the sleep button as the system is configured out of the box.

OS Computer
PC1999 Linux 27
PC1999 Windows 27
PC2002 Windows 2
PC2002 Linux Ubuntu 2
PC2006 Windows 44

But wait, what's going on with that new HP PC taking so much more power suspended than the old HP PC? I looked at the Windows power management control panel and started reading the documentation. It turns out that the old PC was set by default for the sleep button to put it into what Windows calls “standby” state, while the new PC was set by default for the sleep button to put it into “away” mode. Away mode doesn't do much, and is intended for systems that might still be doing some processing without a person sitting there. So it's kind of like forcing it immediately into the quiescent state it would eventually go into if you just left it alone, and the monitor blanks. I changed it to go into suspend state, and then it used just 6 watts. Hibernate state used 4 watts. Michael Chu wrote a great description of how Windows XP power management works.

Here are some details of my configurations.

OS Computer Monitor Speakers
PC1999 Primary: Sun JDS3 Linux; Secondary Windows 98SE PC, Sony Vaio, Pentium III, 500MHz NEC, 14” LCD, 1024x768 Sony
M2000 Primary: Linspire Linux; Secondary: Windows 98SE Laptop, Sharp Actius, Mobile Pentium II, 300MHz integrated integrated
PC2002 Primary: Ubuntu 7.04 Linux; Secondary Windows XP Home PC, Compaq S6000Z, Athlon 2600XP, 1.9GHz Samsung 170MP, 17” LCD, 1280x1024 integrated
PC2006 Primary: Solaris Nevada; Secondary: Windows XP Media PC, HP a1540n, Athlon 64 x2 4200 dual core, 2.2GHz Sharp LL193A, 19” LCD, 1280x1024 integrated
M2007 Debian Linux Tablet, Nokia N800, TI OMAP 2420, 330MHz integrated integrated

Wednesday Sep 19, 2007

Build your own 50W PC

George Ou at ZDnet shows how to build your own PC out of commodity parts using only 50 watts. A crucial point for him is the efficiency of the power supply. He does use regular disks. I would have expected one flash memory "disk" and one spinning disk, but maybe the power management software isn't yet able to distinguish and power down the more energy hungry disk first.

Tuesday Sep 04, 2007

Sun power on a hot day

Yet another scorching day and another energy curtailment at Sun in San Diego. So in my office the lights and workstation are powered off while I work at home with all the windows open. On Labor Day weekend it hit 110 degrees in the east county and over 90 by the coast. At Legoland the most popular attraction was Soak-n-Sail Pirate Shores that dumps a 300 gallon bucket of water on you.

Yesterday SDG&E hit an all-time record demand of 4,636 MW. Although my solar panels hit their peak production in the early afternoon, already by 8am they were producing twice as much energy as my house was using, and the gap is steadily rising. Peak demand for SDG&E is from 4 to 6 pm. Though that's past the peak of my panels' production, my house remains a net generator of electricity through 6pm when it finally begins drawing power from the grid.

Tuesday Aug 21, 2007

Consortium for Energy Efficiency

Gene Saunders wonders about the pace of electric utilities implementing rebate programs for efficient computer servers. I don't have any inside information about what utilities are doing what, but it's worth watching the Consortium for Energy Efficiency: " CEE members include utilities, statewide and regional market transformation administrators, environmental groups, research organizations and state energy offices in the U.S. and Canada."

Their Data Centers and Servers initiative seeks to promote power efficient computing just as they already promote energy efficiency in everything from commercial dishwashers to HVAC equipment. The Spring newsletter mentioned the research done at Lawrence Berkeley National Laboratory, the Green Grid, the SPEC power committee, and the PG&E rebate program.

Wednesday Aug 15, 2007

Energy curtailment day

Today is another "curtailment day" here in San Diego. When SDG&E forecasts that peak demand will come too close to available electricity supply, they notify commercial customers who participate in their voluntary curtailment program. At Sun that means that more lights are turned off, and the air conditioning is turned down especially as we approach the peak energy usage time of day in mid-afternoon. Cal-ISO publishes near real-time charts of current and forecast energy demand.

For employees, and email notice of impending curtailment means it's a good time to come to work in shorts and sandals, aka "San Diego business casual." (It reminds me when I lived in Houston, Texas, there was a campaign to persuade businessmen downtown to stop wearing neckties. Open collar, higher temps, lower A/C, big energy savings.)

Another thing a San Diego curtailment day does is persuade more people than usual to work from home. That certainly saves energy for Sun, with more computers and lights powered off, and less human heat load on the A/C.  For the city as a whole it could save electrical energy, not to mention the gasoline saved by the car trips avoided. For instance when I go home to work I don't need air conditioning (I don't even have an air conditioner) because I can just open windows to get a comfortable cooling breeze, whereas this office building has the usual sealed windows and needs air conditioning even on the most pleasant days. The Sun office and my home are both located near enough to the coast to get shore breezes.

But in certain cases might telecommuting cost energy city-wide? Consider a person who usually works in his Sun office cooled by a high efficiency air conditioner using a 4W Sunray. What if he works from home in the East county where temperatures are much higher, using a lower efficiency home air conditioner and using a 300W home PC? Sunray at home looks better and better.

Tuesday Jul 31, 2007

Power measurements of home computers

I measure power of my home PC's. The one I expected to be worst is best. Sometimes suspending saves a lot, sometimes not. Even turned off some use a lot of power. A Nokia palmtop is good. How about Sun Ray?

[Read More]

Wednesday Dec 07, 2005

Before Eco-Responsibility was Cool

Hey Scott, I was eco-responsible before before eco-responsibility was cool. Not like a friend who endeavored to live so that everything required for life, from food to energy to clothing, could be produced on a single plot of land a few meters square. No, I'm the type of "green" who doesn't want to give up anything, but hears his mother's voice: don't waste, leave some for the next person (or the next generation).

Power from Sun - the real sun

The electricity crisis and rolling blackouts of 2000-2001 hit us here in San Diego before the rest of the west. Day after day while working I kept a window open on the CalISO system status page to anticipate blackouts. It was obvious then, well before the Enron revelations, from the way generating capacity went offline when demand neared capacity that somebody was gaming the system.

We bought a rooftop photo-voltaic generating system sized to meet our household needs over the course of a year. Economically it was about a break-even proposition amortized over the life time of the solar panels verus the current price of electricity per kW-hour. We didn't give up anything, like cutting off appliances to stay within a power budget on a cloudy day. We stayed connected to the grid, spinning the meter backwards to sell electricity back to SDG&E during the day when they need it most, and buying it back at night when they have idle generating capacity. Win-win. Mostly it was insurance, that even if the Electric Robber Barons continued their looting, our price was fixed. We could leave our lights on and thumb our noses at Ken Lay. In the worst case, if the grid did become too unreliable we could always buy batteries and cut ourselves off the grid.

Driving Hybrid

We weren't interested in the Toyota Prius in 2003 - too small and too slow. But in 2004 it got really interesting, with as much interior room, as much acceleration, and better carrying capacity than my full size V6 sedan. Since a few hundred thousand people figured this out before I did, there was quite a waiting list, and I ended up with a 2005 model.

Power Efficient Computing

Sorry, I don't mean Sun UltraSPARC T1. What would I do with over 50,000 transactions per second in my home? Go over to Rich McDougal's cross reference if you want to read about CMT. This is about how I picked a PC from my buddies at HP. My goal really wasn't power efficiency; it was quiet. Power makes heat, heat needs fans, fans make noise, noise doesn't belong in my home. I already had an old Sony PC that did everything fine, except it sounds too much like a lawnmower when it runs. It has an Intel Pentium III chip; you know, back before they started really pushing the clock rate and the power.

So I started by looking at chip power consumption and SPECint2000 ratings. I picked an AMD Athlon processor which had good performance per watt, and nice power management features These features were supported by SuSE Linux, upon which my desktop JDS operating system was based. Several PC vendors used that chip, but colleagues recommended a Compaq Presario and they were right. That PC is so quiet that often if the screen is blacked out you can only tell it's running by spotting the green pilot light.

Little Green Data Center

Thorsten writes about running a Sun Fire T1000 powered by the solar panels on his house. His PV system looks about the same size as mine, but I generate a lot more electricity (3 kW DC, about 2.2 kW AC on a sunny day) - just an advantage of living in San Diego California instead of Hamburg Germany I suppose.

If he only cared about staying within a 1 kW power budget, Thorsten could build a home data center populated with Motorola 68040 processors: 6 watts at 40 MHz. Remember when an 040 was a fast machine? Remember when Macs didn't have fans? No wonder power consumption of data centers has grown so dramatically. But maybe he doesn't want to give up anything either, like thousands of transactions per second.


I am a software engineer in San Diego, president of the Standard Performance Evaluation Corporation (, formerly a mathematician and a violist.


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