디스플레이 어드바이저
보기는 무료, 변경은 Pro
WindowServer가 화면을 그리기 위해 얼마나 일하고 있는지 보여 주고, 그중 일부를 돌려받을 수 있는 변경을 제안합니다.
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
하는 일
- 화면이 열려 있는 동안 WindowServer의 CPU를 코어 하나에 대한 비율로 읽습니다. 읽을 수 없으면 "사용할 수 없음"이라고 표시하고 수치는 보여 주지 않습니다.
- 각 디스플레이의 해상도, 주사율, 그리고 macOS가 더 큰 이미지를 그려서 줄이고 있는지 여부를 보여 줍니다.
- 팁은 읽어 낸 내용만을 근거로 합니다. 패널의 픽셀 수보다 많이 그리는 확대/축소 모드, 외부 디스플레이의 60Hz 초과 주사율, 디스플레이 3대 이상, 그리고 투명도 줄이기입니다.
- "해 보기"는 디스플레이 하나의 모드를 바꿉니다. "유지" 또는 "실행 취소"를 누를 수 있는 시간은 15초이며, 아무것도 하지 않으면 이전 모드로 돌아갑니다.
- "유지" 후 WindowServer를 5분 동안 측정하고 영수증을 만듭니다.
What it will not do
- "해 보기"를 누르기 전에 무언가를 바꾸는 일.
- 변경을 영구적으로 만드는 일. "유지"한 뒤에도 로그아웃할 때까지만 유지됩니다.
- "투명도 줄이기"를 대신 전환하는 일. 그 팁은 시스템 설정을 엽니다.
- 비율을 약속하는 일. 효과 수치는 "최대"로 표시되며 예측이 아니라 상한입니다.
Limits
- 실제로 작은 감소가 있어도 영수증에는 "측정할 수 있는 효과가 없습니다"라고 표시되는 경우가 많습니다. 영수증이 신중하다는 뜻입니다.
- 패널 고유 해상도보다 낮은 모드에서는 글자가 흐리게 보일 수 있습니다. Hedroom은 팁에서 이를 알려 줍니다.
- 15초 동안 Hedroom이 충돌하면 확정되지 않은 모드는 즉시가 아니라 다음에 실행할 때나 로그아웃할 때 원래대로 돌아옵니다.
무료 또는 Pro
측정값과 팁은 무료입니다. 적용해 보는 것은 Pro 기능입니다. 되돌리기는 잠기는 일이 없습니다.
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.