Steam client beta raising Platform Timer Resolution to 1ms / reducing CPU sleep & C states

[[WeBe]tox1c90]

ISSUE:
The latest Steam client beta is permanently raising Windows Platform Timer resolution to 1ms, which differs from the default value of 15.6ms recommended by Microsoft for the idle state.
This leads to the CPU spending less time in its deepest power-saving sleep / C states.

OS:
Windows 10 x64 1803

DESCRIPTION AND STEPS TO REPRODUCE:

I was wondering why my CPU (Intel Core i7 8700K) spends less time than usual in its deepest C7 power states, so I run the Windows power diagnostics tool "powercfg -energy" to generate an energy report.

According to this report, "steamwebhelper.exe" is raising the Platform Timer Resolution from the default 15.6ms to 1ms (see screenshot: https://i.imgur.com/IijZ36c.png).

As soon as I shut down Steam, the Timer Resolution is back to 15.6ms, and the percentage of time the CPU is in the C7 state increases from ~80% (with Steam beta running) to ~95% (measured by the tool "ThrottleStop" which monitors the C states and average power).

This is definitely not the case for the latest final release of the Steam client (I downgraded to check) and started after the new friends list & chat was rolled out to the beta branch.

So I was wondering if it's really necessary for anything of the new stuff to force the Platform Timer to run with high accuracy of 1ms all the time? Or if you could change this behavior to decrease power consumption and in the case of laptops enhance battery life.

[jmccaskey]

You are right, but this is just how Chromium works (which powers a bunch of our stuff) whenever it is actively rendering something. If your PC isn't detected on battery mode it sets the timer resolution to 1ms. Previously you'd be less likely to have Steam UI up that is actually rendering, but now the Friends and Chat windows are rendered by it. If you are actually on a laptop on battery power though the timer resolution should not be forced high by Chromium. This is the same as behavior in Chrome.

https://bugs.chromium.org/p/chromium/issues/detail?id=153139

[[WeBe]tox1c90]

Thanks for the explanation!

But I think it might still be a bug then if the timer is set to 1ms wenn all Steam windows including friends and chat are closed right?

I had friends and chat closed, and steam main windows minimized to systray when I checked timer resolution. So is it maybe trying to render stuff (unnecessarily) in the background?

[The Valeyard]

I've noticed the same behaviour; all windows closed, yet the timer is still at 1ms.

[Left-handed player]

I just came here to say the same thing. I see that the classical programming approach "we can't fix it, who knows how it works, just give up" was used here.