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Now that temperatures have nosedived into winter in the northeast I don't feel bad about leaving my PlayStation 3 running Folding@Home during the day. A digital thermostat keeps the living room at 60 degrees during weekdays so overheating isn't a threat to advancing modern medicine. Leaving something running all day, however, isn't just about heat. It's about electricity, too. Earlier this year I bought the Kill-A-Watt meter and have recently started profiling some devices around my home.

After the PS3 got Remote Start added to Remote Play in the 2.00 firmware I wanted to know exactly how much juice my 60GB PS3 used and when, so I hooked it up and ran some tests. I also found a power consumption comparison of all three systems on the web and compared notes to see how the three consoles compare.

How We Pay For Power
Before we dive in, a very brief note about measuring power and how we pay for it. As an example, a 60-watt bulb uses 60 watts of power while it's on. Getting from watts to your electric bill is easy. Run a 60 watt bulb for 1 hour and you're using 60 watt-hours. Divide that by 1000 and you get kilowatt-hours, so that 60-watt bulb consumes 0.06 kilowatt-hours (kWh) of elecricity. When you pay your power bill, you're paying for kilowatt-hours. I told you it was easy.

This Is My Measuring Stick
I used the Kill-A-Watt meter to take these measurements along with a small 3-prong extension cord on the back to allow me to plug it in to any outlet. You plug the device into the front of the Kill-A-Watt, then plug the Kill-A-Watt into the wall (or battery backup if you're really nice to your expensive electronics), push the watts button on the front of the Kill-A-Watt and wait a few moments for the easy-to-read LCD display to update. It updates in real-time so you can see how power consumption changes based on what you're doing with the device provided you can see the display from where you're working with your device, of course.

Please also note that these measurements are being done on a 60GB PS3, not the new 45nm-Cell chip using 40GB PS3 model that hit retail in November of 2007.

The Tests
First up is the vampire test. The US Department of Energy calls devices that site in a standby mode and draw power constantly "energy vampires". They're not actively being used but are waiting to power up fully on a moment's notice, and some of these devices can use almost as much power when they appear to be off as when they are on.

When the rear switch on the PS3 is on, it's in a standby mode, signified by the red LED being lit on the front of the unit. With the advent of Remote Start we now have two standby modes to contend with, one with Remote Start off, the other with it on. Visibly, the PS3 shows its Wi-Fi light is on and if you have the PS Eye plugged in its power light is on as well.

My Living Room
As points of reference, I measured a few other things in my living room:

Encore USA Wireless Access Point box and Client box: 3 watts x 2.
Phillips DVP642 DVD player, standby: under 1 watt.
Phillips DVP642 DVD player, playing DVD: 9 watts (very little power!)
Satellite TV receiver (non DVR), standby or off: 15 watts.
ReplayTV DVR: 30 watts standby, 34 watts active.
Christmas tree, sparsely lit: 61 watts.
HP Compaq 2510p work laptop, idle: 67 watts.

That's quite a bit of juice flowing in my living room, and I'm ignoring my 2-year-old PC in the corner and its network switch even though I counted its access point alongside the wireless client.

The PS3
Now let's look at what I measured on the PS3.

Standby: 1 watt.
Remote Start Standby: 24 watts.

That's a big jump over regular standby. Let's see where we go when the system fires up.

Idle at the XMB: 158 watts.
Playing a video or music from the XMB: 160 watts.
Playing back Blu-ray movie (Ratatouille) at 1080i: 185 watts.

Video playback and music playback didn't seem to do much of anything to the system's power profile. I figured at this point we were going to see a big jump with Folding@Home, so that's where I went next with my tests.

Surprisingly, Folding@Home showed different power consumption rates when using different visual styles selected from the menu, but once the internal fans kicked in to cool the system down things tended to even out at the high end of the range. It turns out that the screen saver mode where the screen goes dark and updates every few minutes by moving the Folding logo to a different spot saves a good chunk of power over running with the fancy visuals on.

Folding@Home with visuals: 215 watts.
Folding@Home screen saver: 185 watts.

That's 15% less right there, and about 25 watts more than sitting idle at the XMB, but how does that compare to other things the PS3 could be doing? What about games? I took a couple of them for a spin to see what the power profiles looked like.

Ratchet and Clank Future: Tools of Destruction basic gameplay tests: 185-200 watts.
Uncharted Demo during video introduction: 173 watts.
Uncharted Demo during first level gameplay: 203 watts.
Aquatopia: 204 watts.

Right there we can see a little bit of variation when doing things like playing back video but overall the system's at roughly 204 watts when rendering some beautiful scenery like we see in Uncharted or Ratchet and Clank.

How The Other Half Lives
That's quite a bit of juice that can really add up if you leave your system on, but how does it compare with other systems?

One such report by Carl Nelson over at HardCoreWare compares the consoles is out there using a similar tool to the Kill-A-Watt, but the numbers measured for the Wii are so incredibly low that I find them hard to believe. We're talking peak power output when playing a game being just 18 watts when playing Zelda. If I get the chance to profile a Wii I'll write it up for you again, but until then I'm skeptical.

My own peak numbers for the PS3 playing games are higher than Carl's, but he used NBA Live 2k7 as his single test game over 30 minutes of play, so I'm guessing these newest games push the system further than any game before.

The Xbox 360 peak numbers are just about 10 watts lower than the PS3's. This isn't much of a surprise to me, and things might have changed with the newer system designs appearing recently.

Standby power rates are also interesting for the three systems, with Carl's measurements coming in at about 10 watts for WiiConnect24-enabled Wiis (1.3 watts when off) and roughly 2 watts each for the PS3 and 360.

Dollars and Cents
Power isn't free, of course, but here in the USA we have some semblance of a deregulated energy market in that we can choose who our power supplier is even if we can't choose the distributor. Why is this important? Because our electric bills have two dollar amounts on them to put together: the supply charge per kWh, and the distribution charge per kWh. The sum of the two is our effective single price per kWh. (That's after the "service charge" of course, where we pay our electric company for the privilege of, well, paying them even more. But I digress.)

Let's do some math, then. Here's my guess as to the modes I've been keeping my PS3 in during the past month or two now that the weather has cooled:
Playing games: 2 hours per night.
Folding@Home: roughly 50% of the rest of the month.
Standby: the remaining hours.

Assuming a 30-day month of 720 hours:
60 hours of gameplay, 203x60 watt-hours: 12.18 kWh
330 hours of Folding@Home, 185x330 watt-hours: 61.05 kWh
330 hours on standby, 330 watt-hours, 0.33 kWh
That's 73.56 kWh.

I went looking and found a table of average power rates from the US Department of Energy and I'll grab the Middle Atlantic number of 15.13 cents per kWh for myself from August. At that rate I'm looking at about $11 in electricity every month. Roughly ten bucks of that is directly as a result of Folding@Home. Ouch!

Those Hidden Costs
You could extend the costs of gaming to your TV and a sound system if you have one along with your lighting, but most people would agree you'd use most of those doing something else if you weren't gaming.

My lesson from all of this? I should be putting the PS3 in standby when I'm done for the night. Even Remote Play standby all the time is better than cranking along with Folding@Home. And if I feel bad about not contributing I can donate some of the money saved to a good cause.

Image Source: Wikimedia Commons.