A new beta version of App Tamer 3 is available. It offers the option to display CPU temperature in the menu bar and beefs up its Process Details window to be much more useful.
You can now see the CPU and memory usage of all of an app’s helpers and subprocesses. An application’s overall usage in App Tamer’s process list is the sum of the usage of the app and all of its subprocesses, but sometimes it’s useful to see which subprocess is responsible for the bulk of it.
Command-click on a process or right-click and choose “Process Details” from the contextual menu to get the window shown above. It lists all of the helpers and subprocesses with a live display of their memory and CPU usage.
Another very important update in this beta is a fix for a bug which could cause frustrating problems in other apps (most notably Xcode). In App Tamer’s checks to see if a browser was in the process of downloading a file, it neglected to close a file descriptor after the download check. This would gradually run the system out of file descriptors, eventually resulting in some apps’ inability to communicate with sub-tasks. My apologies for the problem!
There are also several minor fixes – a full change history is available on the App Tamer Testing page, along with download links for the latest beta build.
A new public beta version of App Tamer 3.0 is available! The most visible change in recent builds is the ability to display the amount of RAM used by each process. To turn it on, Control-click in the stats area at the top of the window and select “Show Memory Usage”.
Note that the numbers can vary from what you see in Activity Monitor because App Tamer totals up the memory used by any sub-processes and helper apps that are employed by an app or process. It does the same with CPU usage. So the numbers you see for Safari, for example, are the sum of the memory and CPU used by Safari and all of its helper processes (Safari Networking, Safari Web Content, PluginLibraryService, etc). App Tamer will show you a list of these sub-processes if you Control-click on an app and choose “Process Details…” from the contextual menu.
But Wait, There’s More!
So what’s more exciting than that? Well, while adding the ability to collect memory information, I reexamined App Tamer’s process monitoring more generally. I revamped its CPU sampling code, making it more accurate and more efficient. And I eliminated some “slop” in the process throttling engine, allowing it to better control really CPU-hungry processes. Long story short, App Tamer is now much better at controlling CPU usage, keeping it very close to the limit you set rather than bouncing around the target value.
There are also UI improvements to make it easier to see the current temperature on the graph and a clearer indication of how processes are sorted in the process list. Organization of the options in the Stats pane of the Settings window is more logical, and a message at the bottom of the main window explains why Auto-Stop is paused when it’s inactive for some reason.
Share Your Hopes and Dreams (and Bugs)
This is a beta release, so I really want to hear from you if you’ve found a bug, or if you have suggestions or other feedback. Send an email to AppTamer@stclairsoft.com.
Download links and a full list of changes in the beta are available on the App Tamer Testing Page.
I’ve been working on App Tamer 3 for quite a while, beefing up its internals to make it more robust and more efficient, while adding requested features and improving the user interface. It’s finally ready for public testing – I’m excited to hear what you think!
App Tamer displays and controls how apps and services are using your Mac’s processors. There are hundreds of separate processes at work on your Mac – some very apparent, like Safari, and some that run in the background to support apps and the operating system.
All of these processes need processing (CPU) time to do their jobs, and macOS typically manages them fairly efficiently. However, it doesn’t always prioritize those jobs optimally. Spotlight, Time Machine, or a browser running in the background may use processing power that could be otherwise allocated to a task that’s more important to you.
App Tamer lets you take charge of processes that are consuming CPU cycles, slowing them down so they don’t impact your work as much. It can also shift processes to slower, more power-efficient processor cores, ultimately saving power (and battery runtime, if you’re using a MacBook).
And yes, if you’ve encountered a bug in macOS that inexplicably drives a service to use 100% or more of a CPU core, App Tamer can throttle that back to whatever CPU usage you decide to give it. Is photoanalysisd churning away on your Photos library to the detriment of all else? Set App Tamer to run it on the efficiency cores and give it no more that 10%.
New Features and Improvements
Here’s a quick run-down of the major changes in App Tamer. There’s lots more, but these are the highlights.
CPU Temperature
App Tamer now displays CPU temperature so you can see how CPU load is affecting temperature. This lets you make intelligent decisions about which processes need to be slowed down to keep your Mac cool and running quietly. And yes, you can automate app management based on temperature with custom rules (below).
CPU Usage Graphs with More Detail and Accuracy
App Tamer 2’s graphing of CPU usage was pretty rudimentary. Version 3 displays usage data more accurately with customizable colors, automatic scaling and properly annotated axes. It gives you more insight into what’s happening on your Mac.
Switchable Profiles
App Tamer’s ability to fine-tune priorities for apps and background processes is great, but up until now you could only set up one configuration of CPU limits, auto-hide, auto-quit, etc. Now you can create different settings profiles and switch between them. This lets you customize how apps are managed to fit different needs and workflows.
Custom Rules and Focus Filter
You can now set rules to switch between different settings profiles based on a number of criteria. Do you want to throttle CPU-hungry processes when you’re actively working in Final Cut Pro, but let them run when you’re using other apps? Slow down an app when the CPU temperature goes above 70°C? Automatically hide browsers when you’re busy writing? You can do that and more.
And if you use macOS Focus modes, App Tamer includes a focus filter that lets you switch to a particular settings profile when you enter a Focus mode.
All App Settings in One Place
You can browse and modify all customized app settings in App Tamer’s Settings window, making it much easier to review and change how you’re managing each application.
UI and Feature Improvements
I know it’s a cliché, but there are too many to mention. The UI works more smoothly, is translucent and better organized (but no, it’s not been rewritten in Swift UI – App Tamer needs to be compatible with very old systems and has to work consistently across all of them). The contextual menu in the process list offers process details plus web search if you want to know more about a process. You can throttle background processes like menu bar apps. High-CPU warnings are smarter. And a ton of other stuff.
Check out the Beta Testing Page for the long list of changes and fixes.
Under the Hood Improvements
App Tamer’s process monitoring and control engine has been revamped, making it both more efficient and more robust under high CPU loads (because you’re trying to manage your maxed-out Mac, right?). It’s also compatible with the new M5 CPU architecture in the latest Macs, and manages multi-process apps like web browsers and the Spotlight indexer more effectively.
Version 2.8.4 of App Tamer is available now. It fixes bugs and alleviates headaches when using App Tamer in specific configurations.
Most importantly, App Tamer will no longer mess with processes that it isn’t actively controlling. In the past, if a process was stopped, App Tamer would start it running again if none of your settings in App Tamer indicated it should be stopped or slowed down. That could interfere with other apps that were controlling that process, including using Control-Z in Terminal to stop a process using zsh (or whatever shell you’re using). Now App Tamer won’t restart a process if it didn’t stop it in the first place.
There are also small changes to alert messages so that App Tamer’s suggestions are more understandable. And the Priority slider is more clearly separated from other options to show that its effects are separate from the slow / stop features. Note that you need to hold down the Option key to get the Priority slider because it’s a macOS process attribute that’s not always useful. It can help in very specific cases, but App Tamer’s other process controls are more effective.
Speaking of specific cases, you can also hold down the Option key and turn on “Stop this app completely” and “Slow down this app” at the same time. When combined with the “Also slow this app when it’s in front” checkbox, App Tamer will slow the app to the specified CPU limit when it’s in the foreground and will stop it completely when it’s not in front. Again, this is a configuration that’s useful in a few particular situations, but you can do it now – there you go.
And finally, there’s a bug fix for a very quirky issue: You could get a prompt from App Tamer to save a debug file seemingly at random if you happened to be holding down the Option key at the wrong time. (What is it with the Option key in this release?) Anyway, that’s fixed and won’t happen anymore.
A full change history and download links are available on the App Tamer release page. If you’re already running an earlier version of App Tamer, just choose “Check for Update” from the menu in the lower right corner of its window.
Version 2.8.3 of App Tamer is available, bringing a couple of new capabilities and addressing problems with controlling processes during and after system sleep.
First, there a new “Sample Process” command in the contextual menu in App Tamer’s process list:
This does the same thing as the Sample Process command in Apple’s Activity Monitor. It samples the process every millisecond for 10 seconds, recording the call stacks of all threads at each sample point. This is saved to a text file and automatically opened in your default text editor. A sample report can be useful to see what’s happening internally in an app, and can be used to get an idea why an app is consuming a lot of CPU.
App Tamer 2.8.3 also supports Chromium web apps. These are separate site-specific browser apps that you can create with Chromium – they function as separate apps, but use Chromium as their browser engine. App Tamer knows not to slow down Chromium when a web app is in front, since the web app needs Chromium running at full speed in order to show its web content.
Finally, this release is able to correctly slow down processes and run them on efficiency cores during and after system sleep. In previous versions of App Tamer processes would sometimes not be managed at all during sleep, or would run very slowly after waking from sleep. This would eventually correct itself, but definitely wasn’t ideal. The root cause of App Tamer’s confusion has been fixed so everything works as it should.
This update is free if you’ve already got an App Tamer license. Details and download links are available on the App Tamer release page, or by choosing “Check for Update” from the menu in the lower right corner of App Tamer’s window.
Version 2.8.2 of App Tamer is available, giving you the option to save a few pixels of menu bar space while still displaying CPU stats.
A user emailed recently and asked why App Tamer couldn’t just display the stats for performance and efficiency cores without the total CPU usage. He pointed out that the total is, after all, just the sum of the ‘P’ and ‘E’ values and he can add those together himself. Given the plethora of menu bar apps these days, he’d rather do that and save the extra 30 pixels that the overall CPU usage takes in his menu bar.
Well then – I’m not sure why I never thought of that myself 🤦🏻♂️. So here it is – App Tamer 2.8.2 separates control of the overall CPU display from the performance and efficiency core values, giving you more choices in configuring what it shows in your menu bar.
In addition, this release fixes two bugs that could result in apps running slowly even when they’re in the foreground. The first could occur when your Mac wakes from sleep with a throttled app frontmost. The second case only happens if you force-quit App Tamer or if it crashes for some reason (which is fortunately a very rare occurrence). In both instances, apps will now be returned to their correct state, running at full speed and on your Mac’s performance cores if you’re using an Apple Silicon powered Mac.
Details and download links are on the App Tamer “What’s New” page. Or if you’re already running App Tamer, just choose “Check for Update” from the menu in the lower-right corner of its window to get the new version.
A minor update to App Tamer fixes a problem with the recently-released “wake for audio” feature that’s designed to prevent sound from stuttering when apps are slowed down. Version 2.8 failed to recognize when sound was playing through speakers connected via HDMI or DisplayPort – something that’s not uncommon when using an external monitor that has built-in speakers. Version 2.8.1 fixes that.
App Tamer 2.8.1 also adds a few under-the-hood changes that should make things less awkward when App Tamer is forced to quit. Any apps that have been slowed down will be returned to their normal operating speed within a few seconds.
Details and download links are available on the App Tamer release page. If you’re already running App Tamer to optimize CPU usage on your Mac (smart person, you are) just choose “Check for Update” from the menu in the lower right corner of its window.
I’m pretty excited about a new setting in App Tamer because it eliminates the one down-side to using it. In earlier versions, if you used App Tamer to slow down Safari when it was in the background and then tried to play music or a video, the sound could stutter or skip if Safari wasn’t frontmost. Now, App Tamer can detect when sound is playing and keep specific apps awake – just turn on the new “Don’t stop or slow when sound is playing” checkbox and the problem is solved 🙂
Actually, App Tamer 2.8 will automatically turn on this setting for most browsers, music players and audio / video chat apps, so you don’t have to make any changes. Just launch the new version of App Tamer. There is no Step 2 – it just works.
In addition, as the title says, version 2.8 contains bug fixes to make it run smoothly on Apple’s public beta versions of macOS 14 Sonoma. It will also helpfully warn you if you try to slow down an important system service that might negatively impact the performance of your Mac, and delivers fixes for several bugs as well.
Go grab a copy from the App Tamer Release page. You’ll also find a complete list of changes in version 2.8, and a full change history if you’re into that kind of thing.
I’ve come up with a solution to an annoying issue in App Tamer. When you throttle the CPU usage of apps, their attempts to play audio can result in the sound stuttering or cutting out if they’re getting too few CPU cycles. In some cases, this can even affect the sound played by other apps.
Version 2.8 of App Tamer adds a new checkbox to an app’s settings: “Don’t stop or slow when sound is playing”. App Tamer detects when there’s audio playing and runs those apps at full speed until the audio stops. This lets you throttle a web browser to 2% CPU when it’s in the background, but if you’re playing a YouTube video and put it in the background, the video will continue playing normally instead of (possibly) slowing down and stuttering.
So far this works very well – at the expense of letting those apps use more CPU while sound is playing, of course – but I’d like to get more feedback before officially releasing it.
The biggest issue is that there seems to be a bug in Monterey, Ventura and Sonoma that prevents apps from determining whether sound is playing when playback is going through AirPods or other Bluetooth devices. I’ve worked around the problem so it correctly handles all the devices I have here, but I’d really like to have more testing done with other system configurations and devices.
Check the settings for the web browser you’re using – the “when sound is playing” checkbox should be turned on by default.
Play some audio. You’ll see a little speaker next to the app in the process list (see the image over there → ).
Make sure this works with a number of different audio output devices. Use your Mac’s speakers, your AirPods, AirPlay devices, Bluetooth speakers – whatever you’ve got.
Shoot me an email at AppTamer@stclairsoft.com and let me know what version of macOS you’re using and what works and what doesn’t. Hopefully there aren’t any reports in the latter category 🙂
Version 2.7.7 of App Tamer is available. It now includes a button to reset all of its process taming settings back to their defaults, so if you’ve made lots of adjustments and things just aren’t working as you wanted, it’s easy to go back to square one and start over.
App Tamer 2.7.7 also addresses problems when running Windows applications via Parallels Desktop in Parallels’ “Coherence Mode”, updates some of its default settings, and corrects bugs that have been reported since the last release.
For details and download links, go to the What’s New in App Tamer page. Or if you’re already running App Tamer, just select “Check for Update” from its menu to get the new version.
