顯示器建議
可免費查看，更改需要 Pro
顯示 WindowServer 為繪製你的螢幕有多吃力，並提供可能讓它減輕一些負擔的更改。
The problem
If your Mac drives an external display, WindowServer, the macOS process that draws every window on every screen, can use a noticeable share of the CPU. You may see it near the top of Activity Monitor and have no idea what to do about it.
The causes are mostly settings. A scaled resolution makes macOS draw a bigger picture and shrink it to fit. A high refresh rate means more frames to draw. Each extra display adds its own picture. Hedroom reads what your displays are doing and tells you which of those applies on your Mac.
How it works
- Read. While the Display advisor is open, Hedroom reads WindowServer's CPU as a share of one core, at most every 5 seconds. If it cannot read it, it says "Unavailable" and shows no number, never a zero.
- Look at each display. Its resolution, its refresh rate, and whether macOS is drawing more pixels than the panel has and scaling them down.
- Tip only from data. Tips come from what it reads: a scaled mode, a refresh rate above 60 Hz on an external display, three or more displays, or Reduce Transparency. Each carries an impact such as "up to −N% CPU", a ceiling worked out from how many pixels per second would no longer be drawn. When it cannot estimate, it says "No estimate".
- Try it, with a safety net. Try it changes one display's mode. You have 15 seconds to press Keep or Undo. Do nothing and the old mode comes back.
- Measure. After Keep, Hedroom measures WindowServer for 5 minutes and writes a receipt. The change lasts until you log out.
What you will see
The screen shows WindowServer's live CPU with one sentence that follows the data ("WindowServer is light right now." when it is under 5%), then a card for each connected display. A scaled display shows the picture macOS draws as a dashed frame around the one you see, with an "Extra work" chip. Below are the tips, biggest first, each with its reason, an impact chip and a button: Try it, or Open Settings for Reduce Transparency, which Hedroom never flips for you. When there is nothing to change it says "Nothing to change."
After you press Try it, a sheet counts down from 15 seconds with Keep and Undo; Esc undoes. Once you keep a change, it says Hedroom is measuring for 5 minutes and that the change stays until you log out.
A worked example
Example, not real data
A scaled external monitor
Say you have a 4K external display set to "Looks like 2560×1440". macOS draws a 5120×2880 image, then shrinks it to fit the panel, so WindowServer does extra work. The advisor shows the dashed frame and a first tip: use the mode that draws exactly the panel's pixels, with its ceiling.
You press Try it. The display changes, you judge whether the result is comfortable to read, and press Keep. Five minutes later the receipt compares WindowServer before and after. If the drop is smaller than Hedroom can tell apart from normal ups and downs, it says "No measurable effect." and you can press Undo.
Details and limits
它做什麼
- 在螢幕開啟時，讀取 WindowServer 的 CPU，以佔一個核心的比例表示。如果無法讀取，它會顯示「不可用」，並且不顯示數字。
- 顯示每台顯示器的解析度、重新整理率，以及 macOS 是否正在繪製更大的圖像再把它縮小。
- 只根據它讀到的內容給出建議：繪製的像素比面板實際像素更多的縮放模式、外接顯示器上高於 60 Hz 的重新整理率、三台或更多顯示器，以及「降低透明度」。
- 「試一試」會更改一台顯示器的模式。你有 15 秒時間按一下「保留」或「還原」；如果你什麼都不做，舊模式會恢復。
- 按一下「保留」之後，測量 WindowServer 5 分鐘並寫出回執。
What it will not do
- 在你按一下「試一試」之前更改任何內容。
- 讓更改永久生效。即使按一下「保留」之後，它也只保持到你結束登入為止。
- 替你切換「降低透明度」。那條建議會開啟「系統設定」。
- 承諾某個百分比。影響數字會寫「最多」，它們是上限，不是預測。
Limits
- 很小的真實降幅，在回執上常常顯示為「沒有可測量的效果」。這是回執在保持謹慎。
- 低於面板自身解析度的模式，可能讓文字看起來模糊。Hedroom 會在建議中說明。
- 如果 Hedroom 在這 15 秒內當機，未確認的模式會在下次啟動或你結束登入時恢復，而不是立刻恢復。
免費還是 Pro
讀數和建議是免費的。「試一試」屬於 Pro。「還原」永遠不會被鎖定。
Try it changes your display, which is why it, and only it, is Pro.
Questions people ask
Could it leave my screen in a bad state?
Every change has a 15-second Undo, and a change you do not confirm goes back by itself. Hedroom writes a small journal before changing the mode. If it crashes during the 15 seconds, the unconfirmed mode comes back at the next launch or when you log out, not at once.
Does it need any permission?
It asks for no admin password. It reads and changes display modes through the same system calls any app can use, and reads WindowServer's CPU with the system's own ps tool.
Does looking cost battery or CPU?
It reads WindowServer only while the screen is open, at most every 5 seconds, and every 10 seconds while a display-change receipt is measuring, about 6 to 16 minutes. Each read is one run of ps, which took about 20 milliseconds of CPU on the Mac it was checked on.
Will it change my displays by itself?
Never. A display change needs your click on Try it. No rule or schedule can do it.