How to baseline power consumption

If you want to cut the amount of power your IT systems use, you first need to know current consumption. But how easy is it to come up with a baseline and why aren't suppliers ready with an integrated, cross-platform system to help you? Stewart Baines reports.

Over the years much has been written about managing computing assets and ensuring an IT department knows what is connected to the network. More recently, attention has focused on reducing the energy that computers use. But it is a strange anomaly little has been written about bringing these two elements together.

After all, CIOs like hard numbers, and if the IT department decides to reduce the amount of juice that its computers use, the natural question to ask is 'by how much?' Unless that CIO knows how much energy the computers are using to begin with, the question becomes difficult to answer, which turns the whole energy reduction idea into an uncomfortably subjective endeavour.

Even vendors suggest that the computer industry has yet to solve this problem. "Today there aren't many good solutions, easy to use, tailored for this particular kind of problem," admits Tom Bishop, CTO of business services management vendor BMC Software.

"So there's a lot of adaptation that's taking place to help an organisation address the basic question of what the energy consumption is."

This can happen in one of two ways, Bishop suggests. An IT department can take a top-down approach, essentially looking at its energy bill overall and use that as a baseline. The problem with that is it's an opaque approach and doesn't tell you what systems within the IT infrastructure are the biggest power hogs.

And there's another problem, says Rakesh Kumar, a vice president at Gartner. "We can't always measure that because IT doesn't know the figure. It's picked up by the facilities department," he says. "And as a CIO, I have no interest in asking facilities how much they're subsidising me."

Cross-reference data

The alternative suggested by BMC's Bishop is to use existing asset management software to build a detailed database of the system and then cross-reference that with information about expected energy usage to build up a picture of energy consumption.

On the face of it, such a picture might seem a little murky, tempered as it is with a fair amount of guesswork. But there are some ways to improve the accuracy of that approach.

IBM and HP both have software that can tell their own systems management tools how much energy their servers are using, which is great for those IT departments which exclusively run that equipment. But their solutions don't play well with other vendors' systems, argues Gartner's Kumar.

Another option is a data centre modelling tool from Rackwise or such like. These take vendor estimates of power usage and factor them into a software model of the data centre, enabling managers to establish at least a rudimentary baseline model for energy use.

Such solutions are useful for trying to measure energy use in the data centre but what about all those office PCs? Systems from suppliers such as 1E, ScriptLogic and Verdiem can report on PC energy usage as well as helping to govern it, but they don't provide enough insight for Kumar.

"Let's say I have a floor of office space, with 15 individual PCs and some personal printers, some networking devices and so on, and I want to see the energy usage across all that floor plan. What they provide now is pretty good but it's not as integrated as I would like," he says.

Consequently, any serious attempt at baselining energy usage in computing is likely to focus purely on the data centre. Those managers who do try a more holistic approach will find themselves cobbling together figures in exactly the kind of best-guess method that today's CIOs, hardened by calls for better accountability in IT, find distasteful.

Demands for accountability

And who has the time? Asks Tony Lock, programme director at analyst firm Freeform Dynamics. Overstretched IT departments, beset by demands for accountability from the business, may well decide not to prioritise such baselining activity on energy, preferring instead simply to take a stab at reducing power consumption as best they can. And besides, says Lock, most IT departments don't have a strong picture of their assets.

"I sold asset management systems and I've evangelised them for the past 10 to 12 years," he says. "I would argue that most organisations don't know what they own, they don't know where it is, they have no idea who used it and they have no idea what the value of those platforms are."

Harsh words for CIOs trying to monitor anything on the network. Harsher still for those hoping to take a systematic approach to keeping energy consumption in line once it has been curtailed.

For all the rhetoric surrounding green IT, it seems that many firms - and the vendors that serve them - have further to go than we may have hoped.