--- title: "See what’s slowing down your Mac. — iSurge" description: "A slow Mac is almost always CPU, memory, disk or heat. The iSurge window shows which, and the app behind it, on one page." url: https://isurgemac.com/blog/mac-system-monitor-window/ --- [BLOG](https://isurgemac.com/blog/) # See what’s slowing down your Mac. The iSurge window, page by page. A slow Mac is almost always CPU, memory, disk or heat. The iSurge window shows which, and the app behind it, on one page. By Ruthran Baskar · 27 October 2026 · 6 min read IN SHORT - A slow Mac is almost always one of four things: an app keeping the CPU busy, memory running short, a nearly full disk, or heat. - To find which, look at what each app is using right now, next to how hard the whole Mac is working. - The iSurge window shows that on one Overview, with a page for each part of the Mac. Open it with ⌃⌥I. - Click any app for everything about it: its processes, its last hour, its past warnings, and Quit. When a Mac gets slow, the question is always the same: what is it busy with? The answer is nearly always one of four things. An app is keeping the CPU busy. Memory is running short, so macOS keeps moving things out to the disk. The disk itself is almost full. Or the Mac is hot and holds itself back to cool down. To tell which, you need two views side by side: how hard each part of the Mac is working, and which apps are doing the work. That’s what the iSurge window is for. Here’s how to read it, page by page. WINDOW ## How do you see what’s slowing down your Mac? Start with the whole Mac, then narrow down to one app: - **Check each part.** CPU, memory, GPU, power, disk and network each say Normal, or that something is high. - **Find the app.** Sort the apps by what’s high, and the one behind it comes to the top. - **Look at its past.** An app that used a lot once is different from one that does it every day. - **Then act.** Quit it, close what it has open, or leave it and carry on. The iSurge window does each step in one place. Press ⌃⌥I from any app to open it, or click Open iSurge in the menu bar dropdown. You can turn the shortcut off in Settings › General. WINDOW ## The Overview: your whole Mac on one page The window opens on the Overview. Across the top are six cards: CPU, memory, GPU, power, disk and network. Each one has its main number, a few details, a graph of the last two minutes and a word for how it’s doing, like Normal or Charging. Click a card to see the apps using that part the most. Click its arrow to open its page. The Overview: every part of the Mac, the apps using the most, and what the disk could clear. Under the cards, **Using the most** lists the six apps working hardest, by CPU and memory, with how many processes each one runs. An app here is the app you know, with all its helpers added up. [A thousand processes](https://isurgemac.com/blog/a-thousand-processes/) explains how iSurge does that. Beside it are four cards from Disk: **Could be cleared**,**Unused apps**(apps not opened in six months),**Updates**and**Starts at login**. Each opens its part of the Disk page. If the disk is what’s slowing you down, this is where you’ll see it first. WINDOW ## A page for each part of the Mac The pages are listed in order: Overview, CPU, Memory, GPU, Power, Disk, Network, Sound, Bluetooth, Focus and Insights, and Dev once it has something to show. They sit along the top as tabs, or down a sidebar with a live value beside each name. Pick the one you like in Settings › Appearance › Navigation. ⌘1 to ⌘9 jump between them. Each page starts with its big number and its key details, then a large graph, then the apps using that part. A few things each page adds: - **CPU:** load average, temperature, fans, how busy each core is, and each app’s CPU as macOS counts it, with the share of the whole Mac beside it. - **Memory:** where it goes (apps, wired, compressed, cached, free) and a Pressure card: how hard macOS works to fit everything, and how much swap is in use. - **GPU:** how busy it is, and its memory, shared with the rest of the Mac. - **Power:** battery, time left or full in, how much power the Mac draws, and battery health. - **Disk:** free space, read and write speed, and the tools to clear space safely. - **Network:** download and upload speed, the connection, and its own list of the apps using the network, since an app downloading a lot can use almost no CPU. Sound has your Mac’s output and input, and every app’s own volume and output. Bluetooth has your devices and their batteries. When an app is behind a warning, the page’s list marks it. WINDOW ## Graphs that say when and how much Every graph in the window shows the last two minutes. Point at it and a line follows the pointer, with the time and the value of each line at that moment. So when the fan came on a minute ago, you can see what the CPU was doing then, not just now. Point at a graph for the value at that moment. WINDOW ## Choose an app, see everything about it Click an app in any of the window’s lists and its details open beside the page. At the top is how long it has been open and how many processes it runs. Then: - Its memory, as a share of your Mac’s, and its CPU, in cores, with its power, GPU, disk and network. - **Its warnings** over 30 days, 6 months or 12 months: what happened, how often, and when last. Show takes you to the moment. - **Against its usual:** how today compares with its last 6 months. - Where its memory or CPU goes inside the app, and every one of its processes. - **Its last hour**, and its history over months. - Show in Finder, Force Quit and Quit. iSurge asks before it quits anything. Google Chrome’s details beside the Memory page. Esc closes the details. The history stays on your Mac: 12 months, or 6 if you pick that in Settings. WINDOW ## Find anything with ⌘F Press ⌘F, or click the magnifying glass at the top right. On a page with a list of apps, what you type narrows the list. Anywhere else, it finds apps, pages and settings. Use the arrow keys and Return to open one. Choose an app and its details open. WINDOW ## Insights: the last 30 days The live pages tell you what’s happening now. Insights tells you what usually happens. Pick the last 7 or 30 days and it shows your average CPU and memory, the energy used and the data written to the disk, what stood out, the heaviest apps, and the hours your Mac works hardest. Recent alerts lists the last 7 days of warnings. Your first full report comes after 7 days of use. Insights is built from data kept only on this Mac, and it keeps 30 days, deleting older data on its own. WINDOW ## Settings, in a sidebar Settings has its own window, with its sections down a sidebar: General, Appearance, Menu Bar, Notch, Focus Timer, Keep Awake, Disk, Dev, Notifications, Privacy, Updates, License and About. The gear at the top right of the window opens it, and the search finds settings too. ## Not just the window The window is for a closer look. Most of the time you won’t need it: the notch and the menu bar show the same numbers at a glance, and iSurge tells you when something needs you. [Look up.](https://isurgemac.com/blog/look-up/) shows the rest. iSurge needs a Mac with Apple silicon and macOS 15 or later. [See the prices](https://isurgemac.com/pricing/). ## Get iSurge Pay once, yours for good. [Buy iSurge](https://isurgemac.com/pricing/) Already have it? [Download](https://isurgemac.com/download) Requires a Mac with Apple silicon (M1 or later) and macOS 15 Sequoia or later. Notch features need a MacBook with a notch; everything else works on any supported Mac.