How to Calculate Power Consumption for your Server Room

Tips for Calculating Server Room Power Consumption

When it comes to maintaining a server room, there are many balls to juggle. You have to constantly expand the capacity and throughput of the server systems. Demands only ever rise. At the same time, the space inside the room seems to perpetually shrink. Then, the ambient temperature rises, and you draw more and more power.

That last issue is the topic of discussion here. Power draw is one of the most limiting factors when it comes to operating servers and high-end networks. Eventually, you hit a ceiling and don’t have enough power for more expansion. So, as you continue to adapt and redesign your server room, you need to be able to keep track of power consumption. These tips will help you do that.

Add Up the Power Consumption of Every Device in the Room

To calculate the power consumption of a server room, you have to account for the existing hardware. There are a few ways to approach the problem. You can add up the estimated power draw of every device. You can get an active readout for each device and look at real-time consumption. You can also calculate how much power draw is flowing through the server room and then parse out how much of that draw comes from each device.

The easiest method is to use a calculator tool that looks at the amperage, voltage, and wattage of all of your devices and helps you to aggregate them.

For most server rooms, the total power draw will be in the tens of kiloWatts. This total includes every piece of equipment, especially external cooling devices.

Factor in What You Need to Add

Now that you have added up the total power consumption of everything you have, you can get started. The next part is where things get fun (or frustrating).

You want to think about how much space you have in the server room as well as the existing power budget. The power budget is the total amount of power that can be supplied to the server room with your existing electrical infrastructure. If the room draws more power than is in the power lines, things fail.

When comparing your space and power budget, it can help to compare the ratio of the two. You can think about how much power is available in the room per square foot. That highlights the limiting factors that you will ultimately have to design around.

With these numbers in mind, you can list out the additions that you want or need for your server room. This includes all of the devices necessary to meet expanding networking demands. Once again, that also includes additional cooling. Cooling is a major power draw for most server rooms, and you have to budget space and electricity for it.

Shop Around for Efficiency Gains

Once you have all of these numbers, you can search for opportunities to improve your total power efficiency. Sometimes, upgrading older devices will be worth the upfront cost because of improved power efficiency. These improvements can free up room in your power budget and open up more options for how you design your servers and network.

Form Your Energy Budget

You have already calculated your maximum energy budget. The final step in this process will involve the optimization of your power budget around device costs, operational costs, and network demands. This is the idealized budget that is built from the previous calculations.

By committing to an optional energy budget that is less than your maximum energy output, you can inform your purchasing and design decisions. You can focus on minimizing power draw, or you can optimize your power draw/performance ratios. There are many viable approaches. The point is that picking your power budget helps to guide future decisions that will keep power draw in check. By doing this, you ultimately increase the future maximum performance of your server room.

Power consumption is as tricky as it is important. When you utilize calculation tools and think in raw terms of power, you can overcome a number of planning challenges that might otherwise take you by surprise. It’s important to understand the raw limitations in place with your server room and general networking infrastructure. When you do, you can build the best server room possible, with all of your different budgets in mind.

Additional Learning Center Resources