Linux beats Windows 2008 power-saving measures

Power consumption tests point to Linux as the 'greener' operating system

While we've already noted that RHEL conserved more power than Windows Server 2008 in most cases, we'd be remiss if we did not also mention that RHEL drew less power than its Linux brethren in all quiescent tests. The spread for that difference was a low of .5 watts less on the IBM server when the systems were tuned for top performance to a high of over 5 watts less on the HP DL-160G5 server when the systems were in power savings mode.

During the active tests, Windows Server 2008 running in power-savings mode on the Dell box used over 7 per cent more power than the Linux average on the same hardware. But on the IBM and HP DL-360G5 server, Windows Server 2008 pretty much ran on par with the lowest Linux consumer in those tests.

When running in the high performance mode in the active test, Windows Server 2008 used as much as 11 per cent more wattage than the average Linux power draw on the same hardware. That said, Windows Server 2008 had the best power consumption rating in this test run on the HP DL-160G5 server, spending on average about 6.5 watts less than Linux.

The server hardware impact

Server makers responded to our requests to be part of the test bed with several kinds of CPU and disk configurations all housed within 1U hardware casings. Overall, the savings wasn't startling between the highest and lowest number for a server in terms of watts consumed in any test.

There's little doubt that advertised power savings numbers can be achieved, but servers will need to be tuned for both the operating system, as well as the power-savings applications' ability to control which cores are either used or put to rest in a load-balancing situation. Rather than push configurations for core optimizations (we couldn't find settings to do this for the applications tested), we let the operating systems take care of the details. The details, it turns out, was that all of the cores in all of the tests saw at least some activity both in quiescence but also in application use. SMP kernels were used for all tests.

IBM's x3550 was the leanest and greenest, both in terms of CPU 'horsepower' but also power consumed. In quiescent tests, there was less than a 2-watt difference among any of the three operating systems tested in either performance or savings mode. In the active tests, the power draws stayed within that 2-watt range with the exception of when Windows Server 2008 drew 87.8 watts, compared with SUSE's 79.6 watts and RHEL's 78.3 watts in our active test when the systems were tuned from performance.

The dual-quad core Dell 1950 sucked more power overall, but with more cores, it also delivers more computing power. In the quiescent tests, the test where settings were tuned for performance, Red Hat defied logic and used slightly more power than it did in the power savings mode, but otherwise, the results followed as logic and settings expected.

The HP DL-160 didn't show dramatic behavior changes in settings in the quiescent tests, and made Windows 2008 Server a winner in the active, performance-modes test where it seemed to give its best performance.

Join the PC World newsletter!

Error: Please check your email address.

Our Back to Business guide highlights the best products for you to boost your productivity at home, on the road, at the office, or in the classroom.

Keep up with the latest tech news, reviews and previews by subscribing to the Good Gear Guide newsletter.
Show Comments

Most Popular Reviews

Latest News Articles


PCW Evaluation Team

Azadeh Williams

HP OfficeJet Pro 8730

A smarter way to print for busy small business owners, combining speedy printing with scanning and copying, making it easier to produce high quality documents and images at a touch of a button.

Andrew Grant

HP OfficeJet Pro 8730

I've had a multifunction printer in the office going on 10 years now. It was a neat bit of kit back in the day -- print, copy, scan, fax -- when printing over WiFi felt a bit like magic. It’s seen better days though and an upgrade’s well overdue. This HP OfficeJet Pro 8730 looks like it ticks all the same boxes: print, copy, scan, and fax. (Really? Does anyone fax anything any more? I guess it's good to know the facility’s there, just in case.) Printing over WiFi is more-or- less standard these days.

Ed Dawson

HP OfficeJet Pro 8730

As a freelance writer who is always on the go, I like my technology to be both efficient and effective so I can do my job well. The HP OfficeJet Pro 8730 Inkjet Printer ticks all the boxes in terms of form factor, performance and user interface.

Michael Hargreaves

Windows 10 for Business / Dell XPS 13

I’d happily recommend this touchscreen laptop and Windows 10 as a great way to get serious work done at a desk or on the road.

Aysha Strobbe

Windows 10 / HP Spectre x360

Ultimately, I think the Windows 10 environment is excellent for me as it caters for so many different uses. The inclusion of the Xbox app is also great for when you need some downtime too!

Mark Escubio

Windows 10 / Lenovo Yoga 910

For me, the Xbox Play Anywhere is a great new feature as it allows you to play your current Xbox games with higher resolutions and better graphics without forking out extra cash for another copy. Although available titles are still scarce, but I’m sure it will grow in time.

Featured Content

Latest Jobs

Don’t have an account? Sign up here

Don't have an account? Sign up now

Forgot password?