Over a decade ago, I noted that early beta versions of the taskbar clock showed seconds, and sometimes even blinked the colon like some clocks do, but it was removed because the blinking colon and updating time were ruining Windows 95’s benchmark numbers due to the need to keep all of the code paths related to text rendering in memory, as well as the stack of the thread in the Explorer process that updates the clock.
Even though computers are not under the same tight memory constraints as Windows 95, the taskbar still does not show seconds because Terminal Services would have hundreds of updating clocks, and even on single-user systems, the energy efficiency team gives the side-eye to any timer that runs faster than once per minute.
But finally, in 2023, the Taskbar added an option to show seconds. The option is however disabled by default, and it comes with the warning “(uses more power)”. How much power is it using?
The Taskbar team ran power consumption tests to try to convince the energy efficiency team that even though there was an extra cost, that extra cost was not exorbitant.
A member of the Taskbar team told me that their preliminary measurements showed that Explorer consumed 0.417 mW of energy in its default configuration, but the energy usage went up to 5.42 mW if seconds were enabled on the taskbar. This is over a factor of ten, so that sure seems like a big jump.
I’m having trouble finding information on how much energy a laptop screen consumes. This Web site gives a range of 200 mW to 1100 mW active power consumption for a 16-inch screen at 100 nits. Do I believe these numbers? No. Will I report them anyway? I guess I just did.
If we accept these numbers, then an additional 5 mW doesn’t seem quite so bad overall.¹ It’s an extra 2.5% on the high end, or 0.05% on the low end. That’s a loss of 3 to 15 minutes over a 10-hour period.
¹ The energy efficiency team looks at the system as a whole. I mean, sure, Explorer decreasing battery life by 15 minutes over a 10-hour period might not sound like much, but suppose 10 other components come to the same conclusion. Now you’ve lost over two hours. They also look at the aggregate impact of Windows on the global environment and make recommendations like having Windows Update perform its work when there are more low-carbon energy sources available. You can use the PowerGridForecast class to use this information in your own programs. There’s even sample code.
@Raymond Chen:
Members of the energy efficiency team should have a stern talking to with Windows developers who keep adding dozens of new background services to Windows -- when did they last check how much resources and power those use? At least with seconds on taskbar if the users ask for it then it's justified, nobody asked for all those dumb services which just serve to increase the malware attack surface anyway yet most of them are on by default even if Microsoft's own security guidelines say they should be disabled and 90% of users don't need many of them for...
Part of the reasons why I wrote about CompatTelRunner is that it can affect old Windows 7 PCs booting from spinning rust.
I also think that in times where computers have 16+ GB of RAM, we should bother about an operating system needing 200 MB more than the predecessor for absolutely no extra features. After all, unused / free RAM consumes no power, and simply paging stuff in from the hard drive is clearly more power efficient.
Notice that the services consume 0% CPU when not in use. Some of them even shut themselves down when they haven’t been used for a while. Whereas seconds on the taskbar continues running all the time.
@Igor Levicki
1) What kind of memory metric are you using?
2) Have you actually calculated amount of energy for those inactive services and keep on mind that there are several different refresh methods. And don’t forget to account for them being possible swapped out already.
3) And still your complaint is pretty hilarious in light of “modern” browsers…
fair point – but where’s the careful cost/benefit analysis? So far I can’t see any improvements in Windows since Win 7 yet surely the amount of code included and presumably running is much larger in Win 8/10/11. Again, to be fair this is really an empirical question, but I think the odds are quite good that Win11 uses more power at idle or even when being used.
Not to mention the much, much larger environmental cost of the forced hardware discarded when Win10 goes EOL.
There are 63 instances of svchost.exe on my PC right now (and that's with many unnecessary services disabled mind you). For something that by your admission is doing nothing (and something consuming 0% CPU is doing nothing) they surely consume a lot of RAM (707 MB total) -- RAM which has to be powered on, clocked at high frequency, periodically refreshed so it doesn't lose contents (and much more often than once per second). And that's all without taking into account paging and the associated disk reads and writes, etc.
So by all means, please try to convince me that all...