Inside Gaugebar: The Whole Mac in One Glance

Gaugebar is a small Mac utility from 1dot1 that puts a system monitor in the menu bar. A gauge or a live figure sits beside the clock, and a single click opens a panel with CPU, memory, network, disk, battery and the five busiest processes, each with a minute of history. This teardown walks through it card by card and explains the decisions behind each one.

The question it answers is a simple one: why is the Mac slow, loud or warm right now? Activity Monitor can answer that, but it is a full window with tabs and columns, and it has to be found and opened first. Gaugebar keeps the answer one click away, and keeps the most important figure visible without any clicks at all.

The whole picture in one panel

Clicking the menu bar icon opens the panel underneath it. The cards run from top to bottom in the order most people look for trouble: CPU first, then memory, network, disk, power and heat, and finally the processes responsible. The panel keeps updating while it is open, and a click anywhere else puts it away.

Every sparkline holds the last 60 readings, with the newest on the right. A single number says what is happening now; a minute of history says whether it is a spike or a trend, which is usually the more useful thing to know. Right-clicking the icon, or Control-clicking it, opens the options menu without opening the panel, and the same options sit behind the ••• button at the top of the panel.

Every core, at a glance

The CPU card leads with a needle gauge and a large percentage for how busy the processor is overall. The line underneath splits that figure into User, which is apps, and System, which is macOS itself, followed by the load average for the last 1, 5 and 15 minutes.

Below it sits a row of bars, one per core. This is the part that explains a lot of confusing moments. An overall figure of 12% on a ten-core Mac looks harmless, yet it can hide one core running flat out because a single app is stuck in a loop. With a bar per core, that one full bar stands out immediately. The sparkline at the bottom then shows whether the load has just arrived or has been there all minute.

Memory, counted the way macOS counts it

Memory figures are easy to get wrong, and a monitor that disagrees with Activity Monitor is worse than no monitor. Gaugebar shows memory in use out of the RAM installed, where in use is App memory plus Wired plus Compressed. That is the same sum Activity Monitor uses. Cached files are deliberately not counted, because macOS hands that memory back the moment an app needs it.

Beside it sit Swap, which shows how much has been written to disk, and Pressure, which reads Normal, Elevated or Critical exactly as macOS reports it. The card puts pressure next to the used figure on purpose. Pressure is the one that matters: a Mac with 90% of its memory in use and Normal pressure is working as designed, not struggling.

The disk card underneath shows how full the startup disk is, with free space counted the way Finder counts it, including space macOS can clear on demand. Read and Write give the bytes per second moving to and from all disks, and the sparkline shows the two added together, so a burst of disk activity during an update or a large copy is easy to spot.

Traffic as it happens

The network card shows download and upload per second across Wi-Fi, Ethernet and tethering. Both are drawn on the same sparkline and the same scale: download as a filled line, upload as a dashed line. Sharing one scale keeps the comparison honest, since upload is usually a fraction of download and a separate scale would make the two look alike.

Since launch totals everything that has moved since Gaugebar was opened, and quitting resets it. Local IP is the Mac's address on the local network, not the public internet address, which is the one needed for things like connecting to a printer or another computer at home.

VPN tunnels are not added on top. Their traffic already passes through Wi-Fi or Ethernet, so adding them would count the same bytes twice.

See what is busy

The last card lists the five processes using the most CPU right now, measured while the panel is open. Figures are a share of one core, so 100% means one full core, and a busy app on a Mac with ten cores can go past 100%, exactly as it does in Activity Monitor. Using the same convention means a figure read in Gaugebar can be checked in Activity Monitor without any conversion.

There is an honest limit here. The list covers the apps and services running under the signed-in account. System processes owned by macOS cannot be read without administrator rights, and Gaugebar does not ask for those, so they are left out. When the full list is needed, Open Activity Monitor sits in the options menu.

Above the list, Power and Heat shows the battery percentage and whether it is charging, charged or on battery; a desktop Mac shows No battery. Thermal state reads Nominal, Fair, Serious or Critical. Gaugebar does not show temperatures in degrees, because macOS offers no public way to read the sensors, and showing the thermal state is more truthful than guessing. Serious or Critical means macOS is already slowing things down to cool off, which is the practical question behind most temperature checks anyway.

The menu bar shows what matters

What sits beside the clock is a choice, made from Menu Bar Shows in the options menu. Gauge Only is just the icon, its needle following the CPU. CPU Percentage adds the figure beside the gauge. CPU and Memory stacks two small lines, CPU and MEM. Network Rates stacks upload and download per second. CPU Sparkline draws a tiny bar chart of recent CPU use.

The options exist because menu bar space is scarce and people watch different things. Someone on a slow connection wants the network rates; someone compiling code wants the CPU. Gauge Only is the narrowest, which matters on a smaller screen, because macOS quietly hides menu bar items that do not fit.

Update sets how often the numbers refresh: every second, every 2 seconds or every 5 seconds. A system monitor should not become a noticeable load itself, and in testing Gaugebar used around 0.1% CPU while idle. A slower update uses a little less energy again.

Built in black and white

Like the other 1dot1 Mac apps, Gaugebar is greyscale in light and dark mode. The icon is a simple gauge with a needle, and the menu bar glyph repeats it at a smaller size. Without colour, the cards rely on weight and position: bold figures for the current value, lighter text for detail, solid lines for the main measure and dashed lines for the secondary one.

It is a universal app for Apple silicon and Intel Macs and runs on macOS 13 Ventura or later. It needs no permissions, because every figure comes from information macOS makes available to any app. Nothing is recorded or saved apart from the two menu choices, and it never connects to the internet.

How to use it, feature by feature

The same instructions are in the short guide inside the download.

Installing it

1. Unzip the download and drag Gaugebar.app into the Applications folder, then open it. A gauge icon appears in the menu bar, with the CPU figure beside it.
2. Gaugebar is signed and notarized by Apple, so it opens with a normal double-click.

Opening the panel

1. Click the menu bar icon. The panel opens underneath it and keeps updating while it is open.
2. Click anywhere else to put it away.
3. Right-click or Control-click the icon for the options menu without opening the panel, or use the ••• button at the top of the panel.

CPU

1. Read the gauge and the large figure for overall processor load.
2. Check the line underneath for User and System, followed by the 1, 5 and 15 minute load average.
3. Look along the row of bars, one per core, for a single core running full.
4. Follow the sparkline for the last 60 readings, newest on the right.

Memory

1. Read the title for memory in use out of the RAM installed.
2. In use is App plus Wired plus Compressed, as in Activity Monitor; cached files are not counted.
3. Check Swap for how much has been written to disk.
4. Check Pressure, which reads Normal, Elevated or Critical. Pressure matters more than the used figure.

Network

1. Read download and upload per second across Wi-Fi, Ethernet and tethering.
2. On the sparkline, download is the filled line and upload the dashed line, on one scale.
3. Since launch totals all traffic since Gaugebar was opened; quitting resets it.
4. Local IP is the address on the local network, not the public address. VPN traffic is not added twice.

Disk

1. Read the bar for how full the startup disk is, with free space as Finder counts it.
2. Read and Write show bytes per second to and from all disks; the sparkline adds the two together.

Power and heat

1. On a MacBook, read the battery percentage and whether it is charging, charged or on battery. A desktop Mac shows No battery.
2. Read Thermal state: Nominal, Fair, Serious or Critical. Serious or Critical means macOS is slowing things down to cool off.
3. Temperatures in degrees are not shown, because macOS offers no public way to read the sensors.

Busiest processes

1. Open the panel; the five processes using the most CPU are measured while it is open.
2. Read each figure as a share of one core, so a busy app can go past 100%.
3. For system processes owned by macOS, choose Open Activity Monitor from the options menu.

Choosing what the menu bar shows

1. Open the options menu and choose Menu Bar Shows.
2. Pick Gauge Only, CPU Percentage, CPU and Memory, Network Rates or CPU Sparkline.
3. Choose Update to refresh every second, every 2 seconds or every 5 seconds.
4. Turn on Open at Login to keep Gaugebar in the menu bar from startup.

Permissions

1. There are none to grant. Every figure comes from information macOS makes available to any app.
2. Nothing is recorded or saved apart from the two menu choices, and nothing leaves the Mac.

If something does not happen

1. The icon is missing: the menu bar may be full. Quit another menu bar app, or pick Gauge Only for a narrower icon.
2. The busiest processes say Measuring…: the list needs two readings to compare, so it fills in after the first update.
3. A system process is not in the list: that is expected, as those need administrator rights to read.
4. Read and Write say Unavailable: the Mac did not report disk statistics, which can happen in a virtual machine. Everything else still works.
5. Open at Login does not stick: move Gaugebar.app into the Applications folder first, then turn it on again.

Get Gaugebar

Gaugebar is available on 1dot1 as a single download, with the guide, a README and the licence inside the zip.

Get It Now