1. How did LBNL get interested in this? 
    • One of our sons--Nathaniel Mills--wanted to build a gaming PC.  When we saw the potential power requirements we turned it into a scoping study that eventually grew into the current project. He is first author on the original journal article.
  2. Who is funding this work and does the industry have input?
    • Our current sponsor is the California Energy Commission, through a R&D program called EPIC which runs on funds collected through electricity tariffs.  We assembled an industry advisory board and work with consultants and other groups to ensure that the research is relevant and usable (more here).
  3. What is interesting about this work? 
    • It's a rare example of a specific end-use domain that has been unstudied.  There is potential to make a big difference. While the energy use of conventional PCs has been falling for some time (thanks in large part to energy policies), that of gaming PCs continues to rise, as do the number in use. Understanding this incredibly complex energy end use makes the work is quite interesting.
  4. What do you think are the most effective ways to cut energy use by gaming PCs and why?  
    • There are three main "prongs": hardware, software, and user choices.  On the hardware side, the graphics card ("GPU") is the greatest single node of energy use, but power management and improved power supplies and CPUs are also important.  We have seen a huge range in energy use per unit of workload (e.g., frames per second rendering rates), and so are very optimistic in that regard.  On the software side, we are confident that given games can be designed with greater efficiency in mind without compromising user experience. On the user side, there are many untapped operational fixes (such as turning off unused slots in the motherboard).
  5. What are the biggest challenges in this work?  
    • The full magnitude of the problem and the diversity of efficiency opportunities are barely if at all on gamers' radar, so there is a large learning curve to address.  There are also no widely accepted benchmarks of energy use or test methodologies, and so this is the place we must begin so as to have a common framework for talking about and describing energy use and savings in a consistent manner.
  6. Have you found any surprises in this work?  
    • Many. One example is that we initially thought that virtual reality would bring with it some intrinsic energy savings (since the displays in the goggles are so small), but have learned that the computational requirements of the graphics cards (a shift from 30-60 frames per second to 90-120 fps) can increase power requirements, although not in every case. Advanced "Foveated Rendering" can relax the fidelity in the periphery of the VR view range, and thereby reduce energy use significantly. Another other major surprise is how much energy is used in data centers for cloud-based gaming as well as the Internet infrastructure connecting those servers to the gamer (see our answers to various common questions about that below). We also found that some gaming systems use almost as much energy in idle or navigation mode as they use during active gameplay.
  7. From what you know so far, what kinds of efficiency policies and programs might be most effective?  
    • As this market segment is virtually untouched by the energy policy community, a wide array of possibilities exist.  These include component and perhaps even game labeling, full system labeling, consumer information, utility financial incentives (e.g. rebates), and R&D into improved technology. If voluntary strategies don't suffice, policymakers may look to mandatory efficiency standards, although that would be quite technically problematic to implement.
  8. How has the gaming community and industry responded to the research? 
    • We've had the whole gamut of reactions. Many people react to brief news summaries without taking time to read the actual reports (we're heard "TLDR" more than once).  Some gamers tend to compare their particular machine and personal utilization to our "average" one and balk at any differences.  Of course, no one person is average but averages are relevant for extrapolating to large scales. Lots of people assert that it's not cost-effective to save energy in gaming, but this is a red herring insofar as some things can be done that cost nothing, other things will have a reasonable payback time, and others will yield non-energy benefits such as noise and heat reduction that are certainly valued by gamers.  Some people are in disbelief that energy use can be reduced without taking a user-experience hit, but the data show clearly that this is quite possible.
  9. From comments in the blogosphere, it seems that  some gamers don’t much care about the environmental impacts of gaming - what’s one thing you would say to them? 
    • Many people say that they simply don't care about energy or environment and that gaming is a necessity rather than an option.  We are actually not advocating that people stop gaming or even reduce it, only to look at ways of specifying more efficient rigs.  Even if environment isn't regarded as important, inefficient gaming PCs also release tons of heat and are noisier than efficient ones, so, it's a win-win proposition to improve efficiency ... not to mention saving money. The younger set may count on their parents to pay energy bills, when they become aware it will be a shock. Others care, but think our attention is misplaced.  It's easy to dismiss any particular use of energy as being insignificant, and easy to point to "big polluters" elsewhere.  The reality is that energy use is highly diffuse and there is no magic bullet or single type of use that will solve the problem.  The inconvenient truth here is that gaming computers use more energy than previously thought, with the more power-hungry ones consuming as much as four efficient refrigerators. And gaming PCs are about the only piece of equipment left that has had a free ride in terms of no energy labeling, standards, or incentives for improvement ... this double standard will no doubt soon be resolved.
  10. Are there free/cheap things that gamers can do to monitor their energy use, and if so, is there a place for crowdsourced data?  
    • Crowdsourcing would be a great idea.  We don't know of any sites that do it at any scale.  However, before this could be done meaningfully there would need to be standard, accepted methodologies for measuring ... otherwise we will just have a lot of inconclusive apples-and-oranges data.  Developing standardized methods is one of the goals of our work.
  11. What single piece of advice would you give to someone building a new gaming PC? 
    • Carefully do the math to determine your total cost of ownership (purchase + operations).  A $2000 machine could use again that much energy over just a few years....   If you're in a place with high electricity prices the operating cost can be particularly prohibitive.  Take up the challenge of improving efficiency as a cool project to geek out on on!  Check out greeningthebeast.org for lots of practical tips based on our research.
  12. Lots of different questions have come in about cloud-based gaming:
    • Does cloud-based gaming save energy?
      • Unfortunately, no.  In fact, cloud-based gaming requires significantly more energy than similarly powerful equipment located in the gamer's home -- three-times as much in the most extreme cases we identified. A key reason for this is that data centers hosting the high-power gaming servers require very substantial ventilation and air conditioning. To this one must add the network energy between the server and the gamer. And, of course, the user-side equipment still uses some energy. The added energy is even greater if the home system is less graphically powerful than the cloud-based system and/or the games run in the cloud are more compute intensive than what the gamer would select on their own local equipment. The impact will be minimized by very "thin" clients on the user side.
    • How much of this extra energy is associated with the network as distinct from the data centers?
      • In our calculations for PC cloud gaming, the datacenter is responsible for about 340 Watts of power per user and the network an additional 180 watts.  So, both components of the overall gaming environment are quite important. The corresponding values for console cloud gaming are 180 and 120 watts, respectively. Energy use of the network is significant -- you can delve more deeply into that via this article.  It is important to note that efforts to make networks more energy efficient have achieved dramatic improvements in recent years and can be expected to continue to do so.
    • Does cloud-based gaming (potentially) provide environmental benefits by reducing the need for local hardware, which means less e-waste, etc?
      • We haven't evaluated the solid-waste side of this topic, but it's a good question. Of course, if componentry is shared among multiple gamers, that can translate into less gear per gamer (although, only one gamer can use a given GPU at a time, so those servers are enormous -- typically 8 GPUs). Two countervailing factors come to mind.  On the one hand, if centralized technology lasts longer there is less solid waste per hour of gaming use. However, turnover could well be faster in data centers, given the pressure to keep with the latest gear, and longer operating hours than home-based systems. Also, the datacenter facility itself and the associated infrastructure (heating and cooling equipment, etc.), as well as the networking gear represent equipment that is not needed for distributed gaming in existing buildings.
    • How can this new source of gaming energy use best be managed?
      • Like most energy-using enterprises, a given amount of work can be achieved with widely-ranging efficiencies. Herein lies the main opportunity of energy efficiency in general and green-gaming in particular. Energy use for cloud gaming will depend on the specs of the servers, how fully the servers are utilized, efficiency of the data centers, efficiency of the network equipment used to link gamers to the data center, and the energy used by the gamer's local device. The local device, will consume some power, although hopefully it employs power management that minimizes that particular load.  The extent of power management varies very widely across gaming devices (see Fig 22 in our report). The key is improved infrastructure efficiency in data centers (primarily air conditioning and ventilation) and how clean the grid is that serves them. The energy efficiency of Internet infrastructure is also critical, and has shown a strong trend of improvement in recent years. When cloud gaming, the client on the user's side should be an "thin" and efficient as possible, as it uses power even when the rendering is performed remotely.