iStat Menus 4: Menubar System Monitoring, Improved

Sometimes it’s good to know what’s going on beneath the hood of your Mac. Keeping track of memory and processor usage helps you manage open apps and current tasks, ensuring that your computer never grinds to a halt because you’re doing too much at once.

iStat Menus is one of the more popular apps to help you keep tabs on your Mac, with its advanced monitoring of memory usage, processor usage, network bandwidth, hardware temperatures, and much more. It just got a major new version upgrade, with a slew of new features — including history graphs, calendar events, and an improved interface — so we thought we’d take a look to see how this new release stands up.

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Wait: What is iStat Menus?

iStat Menus offers several monitoring systems for checking up on how your Mac’s running. You can see CPU usage, how much free space is on your hard drive, how much RAM is in use, what temperature your hardware components are at, how much data you’re transferring on your network, and much more. The best part is that each of these sits in your menubar, with at-a-glance information that can be expanded at the click of a button. You can have graphs or numbers (or both) for the key data in the menubar, then a breakdown of usage in the drop-down menu.

My menubar, including the iStat Menus, uh… menus for CPU, memory, network bandwidth, sensors, and time/calendar monitoring.

All told, you have eight menus that can be toggled on or off: CPU/GPU, Memory, Disks, Network, Sensors, Battery, Time, and Combined (which combines the individual menus into one). The Time menu serves as a great replacement for Apple’s default menubar clock, with a selectable calendar that shows events (finally) and a world clock (for seeing what time it is in other parts of the world), while the Battery monitor similarly improves upon Apple’s own offering. All of the others tap into information that you’d otherwise have to juggle multiple apps and windows to monitor.

The iStat Menus Preferences, which is oddly not accessible from the menus anymore (but rather must be opened like any other app).

iStat Menus has been around for years now — we first reviewed it back in May 2010, when the third major revision was released. Back then we praised it for its detailed stat-tracking of nearly every all of your computer’s resources, with the added bonus that you could pick and choose just the information that’s important for your menubar. Let’s see what the new version brings to the table.

What’s New?

iStat Menus 4 adds history graphs, more stat-tracking, and a new layout. The changes in design are subtle and of mixed effect — information in the menus, which has been slightly re-ordered and given better contrast, is now clearer and easier to digest, while the Preferences have been streamlined. The app is now more user-friendly on the whole, but there’s strangely no option to bring up the Preferences, Activity Monitor, or Disk Utility direct from a menu.

History graphs for the different monitoring systems give a much better indication of usage over time. For CPU, memory, network activity, and sensors, these graphs come in three flavors: one hour, 24 hours, and seven days. Load averages and disk activity add a fourth graph for the past five minutes. Most of these graphs are hidden from view — only the one hour memory, network activity, and CPU graphs show up when you click on the relevant menu item.

Look at all the graph prettiness. There’s another set of graphs attached to the Uptime section.

To display them, mouse over the relevant information. Most menus hide information within submenus attached to their elements. The Sensors menu has a different set of history graphs for every single component being monitored. There’s an abundance of information available for the curious or obsessed. But it stays out of the way for more at-a-glance style monitoring. This seems like a good compromise — the extra detail you may sometimes want is there, but you won’t notice it unless you go looking. (And really, does anyone obsessively monitor graphs of the same information over time scales? Surely one graph is enough 90% of the time?)

I love the new color-coded memory usage graph. All it’s doing right now, however, is reminding me that I need more RAM.

The few days I’ve been using iStat Menus 4 haven’t given me enough data yet to see any reliable patterns or trends, but these history graphs should be a great helper in keeping my computer running smoothly and diagnosing unusual activity.

Doubly so in the case of network activity, since the new version adds per-process bandwidth monitoring. The five most recent processes to transfer data on the network show up at the bottom of the Network menu, with their current transfer speed displayed alongside the process name. Unfortunately it doesn’t offer tracking of total usage per process, or display upload transfer rates — either in the current session or long-term. Little Snitch is still the king of serious network monitoring, but this is great aid to doing quick checks of at-this-very-moment bandwidth usage. If there’s significantly more network activity than you expect, you’ve now got a good chance of identifying the culprit with a glance at iStat Menus.

You can see per-process network traffic for the five most recent apps to send or receive data, but it’s not tracked long-term like other data and it’s never clear whether you’re seeing upstream or downstream information.

GPU monitoring was added in the 3.16 update, but it consisted of just a bar indicating VRAM usage. There’s now also a frames-per-second counter, which is sure to please (or displease, as the case may be) the nerdy among you. There’s no graph to go with this one, however.

Sensing a Change

As before, you can set up rules that dictate the minimum speed your fans spin at in different scenarios. You still can’t automate this according to the temperature of a component, however. The addition of history graphs for each component negate this somewhat by enabling you to fine-tune your settings. If your CPU is running consistently hot, you’ll see it clearly on the 24-hour and 7-day history graphs, and then you can adjust your rules accordingly.

The Sensors menu is still a bit buggy — those fan-speed sliders are not in the right place according to my “Medium” settings. Note that every single item in this menu has a set of three history graphs associated with it.

With this new version of iStat Menus, it’s easier than ever before to notice anything untoward with your computer. But, as before, you’ll only be able to use it for monitoring — it’s an aide in any diagnoses of problems, and a great help in lots of little inconsequential things, nothing more. Mostly it’s useful for battery monitoring, checking the time elsewhere in the world, and quickly looking at your calendar — the other monitors are nice to have, but hardly important to the majority of users’ workflow.

The improved calendar rocks, and now serves as one of the better menubar calendars going around.

Should You Upgrade?

It’s easy to get lost in the excitement of new bells and whistles without thinking about whether you need them, and in this case it comes down to your use cases. If the graphs don’t excite you, there are probably just three things to consider: The new Time menu, per-process network monitoring, and Retina graphics (which it has, by the way).

The changes to the Time/Calendar menu make iStat Menus one of the best menubar calendars around, while the per-process network monitoring — as rudimentary as it is — offers quick and useful insights into data transfer rates as they happen. iStat Menus 4 is the same menubar monitoring app I’ve come to know and love, made better — with more features, an improved layout, and further integration into the Mountain Lion ecosystem. But if you don’t need history graphs, the price of an upgrade may be a little too steep at this stage.


iStat Menus 4 makes an already-great app better with an improved design, history graphs, Retina support, per-process monitoring, and calendar events. It's fantastic for keeping you on top of CPU/memory usage, disk space, battery life, network traffic, and more, right from your menubar.

  • joe

    thank you for review, you give score 9/10 ? hmmm i think it worth a try

  • nemesit

    the design got really bad istat menus 3 looked much better but i guess the urge to create uneccessary details for the retina mac icons was too strong -.-

  • A. Davis

    “The app is now more user-friendly on the whole, but there’s strangely no option to bring up the Preferences, Activity Monitor, or Disk Utility direct from a menu.”

    Its not obvious, but its there. Open the iStat Menus app. From the menu bar, click on Stats, then on “Show App Launcher in Menus”.

    Now, clicking on any of the options, say CPU for example, at the bottom you’ll see five icons for Activity Monitor, Console, Terminal, System Information (the fully detailed one, not what you get when you choose Apple > About this Mac), and iStat Menu’s itself. Unfortunately, I don’t see where you can edit this. I would prefer to remove Terminal and add in Disk Utility, but at least the other items you mentioned are there. The inclusion of iStat Menus itself makes for a faster solution than using LaunchPad or opening up Finder > Applications.

    • Richard Moss

      Oh my, that is an obscure place to put the setting. Thanks for pointing that out.

  • A. Davis

    Something that’s not obvious, but at first glance appears to be missing… in version 3 you could see per core CPU usage. Now clicking on the CPU menu let shows one graph for all cores and hovering over that graph shows the hour, 24 hours, and 7 days view, but its still combined cores. However, if you hover over the “User, System, Nice, Idle” portion under the combined CPU graph, it will expand to show the usage per core. So its still there, just not as obviously as it used to be.

  • GV

    Strange… When I have iStatMenus check for an update it states that version 3 is the latest version and I already have it installed.

  • Jos

    You have enough memory, inactive is basically free memory, but it’s not freed up until you run out of actual free mem, that way if you open something up again that’s still in the inactive ram it doesn’t have to be loaded again. It’s ‘nix memory management as opposed to windows memory management.

    • Richard Moss

      I’m aware of that (so far as understanding the theory at an undergraduate level), but it doesn’t seem to be quite so straightforward in this case. Most of that inactive memory, for one reason or another, seems to be set aside for Firefox (perhaps because I have a LOT of tabs open but not loaded).

      When I open a new app, what ends up happening is that my computer loads up more swap memory instead of freeing up the inactive RAM (which of course leads to massive slowdowns because page ins/outs take a relatively long time). Often a couple of apps then become unresponsive for several minutes. If you could explain why it doesn’t free the inactive memory to me I’d be grateful.

      (And I need more RAM because I want to keep Parallels open in addition to all the stuff in use most of the time, and I want to give it at least 1.5GB of RAM. Last time I tried adding Parallels to my regular workflow my computer froze and eventually said that it’s out of memory.)

  • Tamer

    WIth version 4, I can no longer see the menubar clock on the menubar when I choose combined. There is a “Time” tab buried in the combined drop-down menu, but nothing on the menubar. This sucks…

    • Richard Moss

      Why not just remove the Time option from combined? It’s not an all or nothing option—you can have the Time menu on its own and then all the other menus you want in the combined menu.

      • Tamer

        Yep, I should have thought of that. Actually, I discovered that you don’t even have to drop Time from the Combined — you can tell it to put it on the menubar. I must have been having a senior moment. Thanks for straightening me up.

  • phil

    i stick with version3 as long as i might get version4 as bycatch of a future software bundle, as i see no reason for a paid upgrade with those little changes.

  • Ian

    I personally think Istat menus 4 is a drastic downgrade aesthetically to istat 3… it’s garish, bland and far too windows like it the way it shows graphs and bars. In the settings it also looks like someone has went overkill with the emboss tool in PS. I rarely get this riled up about independent devs but I loved this company once – it appears they have turned istat into the same crap too!


  • Stephen

    is there a way to monitor the internet bandwidth (usage, GB) per computer on my network? if so, I still haven’t found it.

    through out my research for that “tool”, i’ve seen A LOT of people searching for a way to monitor internet usage per device, say iPad, iMac and PC. is there, ANYWHERE a software that’ll do that?!