Windows battery life & secondary impacts

Yet another article in the ongoing issue concerning the lackluster battery performance of Windows on portable computers, this time from Jeff Atwood of Codinghorror, with Anand Lal Shimpi of Anandtech weighing in on the situation.

What I find most interesting about this problem is not so much the problem posed to those using Windows based laptops (I feel for you), but rather the comparison with OS X on identical hardware. When you isolate the issue to identical use cases on identical hardware, you eliminate the screen, the networking, the keyboard backlighting, and so on. Finally you are left with the software and how it uses the hardware.

From a practical standpoint, we can discount the screen and the network and even the SSD since there is no “spindown” state and the power consumption is a straight line. Which leaves us the use of the CPU and GPU. It is clearly demonstrated that software optimizations can have a huge impact on efficiency and we’ve only seen the beginning from Apple. 10.9 Mavericks brings even more finely grained CPU and network scheduling.

Now my interest is in a different use case: Virtual Desktop Infrastructure. The existing and upcoming CPU optimizations implemented in OS X are potentially as useful in a shared CPU configuration like VDI as they are on a notebook computer.

This makes me wonder about the power efficiency of using Windows in a VDI installation. From the power consumption tests, it’s eating up more CPU to do the same job than does OS X, to the order of 50% more. Granted, in some tests, this results in slightly faster processing time, but only of the order of 15% in the best case scenarios.

On the one hand, that’s awful.

On the other hand, this type of system efficiency will become a much more pressing issue for Microsoft now that they are making their own hardware and need to be competitive with iPads and MacBooks on a work/watt basis. Which means that if Microsoft gets its act in gear, and can improve the overall efficiency of the CPU usage, we should be able to see even higher density workloads on the same server hardware. But it’s unlikely that this kind of thing will be retrofitted onto the existing Windows 7 systems and will only be available on future Windows 8 releases.

In the meantime, just use OS X on your portable computers if you want to get the most out of them, and hope that maybe some day we’ll see OS X as a VDI hosted option.

Although racking the new Mac Pros is going to require some innovative thinking…