Questions tagged [performance]

Questions dealing with performance of Apple hardware or software, especially about troubleshooting or improving poor performance.

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kernel_task hundreds of % CPU yet cpu frequency is being lowered

I'm trying to solve the mystery of a crazy high cpu usage on kernel_task. MacBook Pro (Retina, Mid 2012), 2.7 GHz Intel Core i7, Yosemite 10.10.2 I saw some advice to download the Intel Power Gadget....
justingordon's user avatar
13 votes
5 answers
8k views

How to keep an SSD in shape on Yosemite?

As of OS X 10.10, Apple uses kext signing. Ever since it has become difficult and dangerous to manually activate TRIM for third-party SSDs on OS X. That means users with non-Apple SSDs will sooner or ...
n1000's user avatar
  • 7,684
168 votes
10 answers
168k views

How to simulate slow internet connections on the mac

What's a good software solution to slow down internet connections on the mac for testing and simulations? My primary need is when testing code in the iPhone / iOS simulator, so slowing down the ...
aneuryzm's user avatar
  • 5,419
41 votes
13 answers
47k views

Why is kernel_task using so much CPU?

I have a Macbook Pro Retina with the following hardware: Model Name: MacBook Pro Model Identifier: MacBookPro11,1 Processor Name: Intel Core i5 Processor Speed: 2.4 GHz Number of Processors: 1 ...
Addison Crump's user avatar
147 votes
2 answers
231k views

How to investigate high kernel task memory usage?

I was using my MacBook Pro (with 16GB of RAM) as usual and out of blue I've this popup that: Your system has run out of application memory. To avoid problems with your computer, quit any applications ...
kenorb's user avatar
  • 12.7k
84 votes
16 answers
80k views

Can I manually limit the %CPU used by a process?

I would like to limit the amount of CPU time dedicated to certain processes (e.g. Firefox, Safari, ...). I can't understand why such programs, even when not used (nothing loading, no animations, ...
Pietro's user avatar
  • 1,159
56 votes
15 answers
75k views

Why would I disable swap file in Mac OS X?

I came across a thread about installing an SSD drive in MacBook Pro. Someone in the comments also recommended to disable the swap file but didn't say why: sudo launchctl unload -w /System/Library/...
Dan's user avatar
  • 4,998
13 votes
5 answers
35k views

What's the fastest connection speed / shortest elapsed time using Migration Assistant?

When using Migration Assistant to move users, files, and folders from an old Mac to a new one, you have a few different choices, depending on the Macs involved. Presuming that both Macs have ...
Negrino's user avatar
  • 2,611
11 votes
2 answers
55k views

Using memory with a higher MHz rating? [duplicate]

Can MacBook Pro's successfully support and fully exploit RAM of a higher MHz rating than that which they ship with? For example, take my 15" MacBook Pro (Late 2011) that ships with 4GB of 1333MHz ...
Baumr's user avatar
  • 2,816
170 votes
11 answers
188k views

WindowServer high CPU on Yosemite

This is a follow up to So my Yosemite install is slow - what to do? Since installing Yosemite a week or so ago my machine is very sluggish. I am a web developer so I change windows/apps a lot. ...
Jake N's user avatar
  • 2,288
32 votes
1 answer
38k views

What does it mean when a %CPU exceeds (# of cores) x 100%?

Several responses to a question I asked earlier suggested I try Opera kiosk mode, so I decided to download it and give it a try. Once the download had completed and the disk image was being verified, ...
Kyle Cronin's user avatar
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20 votes
5 answers
86k views

Boot hangs on grey screen (even when booting from USB drive with fresh OS X install)

My MacBook Pro 15" Late 2011 (MacBookPro8,2) with AMD Radeon 6770M exhibited display corruption and associated system crashes/resets over a period of two weeks before it entirely failed to boot. The ...
geevs's user avatar
  • 201
11 votes
2 answers
16k views

MacBook Pro with Mountain Lion freezes frequently (full screen Flash in Chrome, Messages, HTC on USB)

Problems following an upgrade to Mountain Lion on a 13-inch, Early 2011 MacBook Pro (MacBookPro8,1 with Intel HD Graphics 3000). With Google Chrome, I was watching YouTube video fullscreen – Flash ...
Vivart's user avatar
  • 499
10 votes
2 answers
9k views

Is it possible to disable CPU throttling on a MacBook Pro with a completely dead (not recognized) battery?

I have a MBP late 2011 running El Capitan, recently my battery died (x over the icon and "no battery available" in the dropdown.) I've noticed since then that CPU intensive tasks are very slow, and I ...
Aaron Robeson's user avatar
10 votes
9 answers
62k views

Checking for bad blocks without formatting

My Mac tends to pause every now then when preforming simple tasks such as right clicking, opening menus and typing (It actually just froze when I started typing this question.). I've read in a few ...
Ron's user avatar
  • 233
10 votes
3 answers
36k views

How can I disable CPU throttling and CPU disabling?

On a 2011 17" MacBook Pro (i7, 10.6, 16GB ram) I do not have any options in the energy saver preference panel to control CPU throttling. I need to be able to disable CPU throttling for short periods ...
Adam Davis's user avatar
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4 votes
1 answer
2k views

How can I disable CPU throttling on Late 2006 MacBook with no battery? [duplicate]

The problem I am experiencing is that if the battery is not present, the CPU is automatically throttled. I have done some searching and have found that this is apparently by design, "in case the ...
Michael's user avatar
  • 1,333
73 votes
5 answers
72k views

How to monitor and control thermal CPU throttling in OS X?

I recently came across the Intel Extreme Tuning Utility for Windows. I tried it under Bootcamp Windows and it was very interesting to learn in what situations my MacBook Pro's (mid2012) CPU is doing ...
n1000's user avatar
  • 7,684
22 votes
2 answers
37k views

How does 'stuck' (in results of 'top') relate to 'not responding' (in Activity Monitor), 'spin' or 'hang'?

In results of top commands, I sometimes see stuck. Apple's top(1) OS X Manual Page does not explain this use of the word. How, if it all, does stuck relate to the following? not responding – may ...
Graham Perrin's user avatar
16 votes
2 answers
10k views

How to stress a MacBook Pro Retina?

I need to stress my rMBP components (e.g. CPU/GPU/RAM) without loading any additional software tools. Background - My rMBP has a hardware fault (similar to this issue) which causes system freezes ...
Mannie's user avatar
  • 288
3 votes
2 answers
6k views

How would I identify what's causing my Mac to permanently hang on shutdown?

Whenever I try to shutdown or reboot my Mac (Macbook Pro 15" Retina late 2013, OS X 10.11.3) it closes all programs like normal and then it goes into that black screen with the progress bar. When it ...
Adriano C R's user avatar
57 votes
9 answers
62k views

Time Machine ridiculously slow after El Capitan upgrade

I recently updated to El Capitan, and told Time Machine to backup. It got stuck on Preparing Backup for hours, so I stopped it, deleted the InProgress file, rebooted and tried again. After ~30 mins, ...
CraftedCart's user avatar
  • 1,510
13 votes
2 answers
3k views

vm_compressor=VM_PAGER_DEFAULT in Yosemite caused freeze when physical memory was full

The memory compression caused frequently lag so I tried turning it off by using the command sudo nvram boot-args="vm_compressor=1" The lag was gone but I got crashing freeze when I opened ...
keithyip's user avatar
  • 249
10 votes
1 answer
14k views

Where are crash logs after a system freeze?

When your entire macOS freezes up and restarts, are there crash logs or core dumps to diagnose the problem? I would in particular like to know which kernel module was active at the time of the crash. ...
Jo Liss's user avatar
  • 313
7 votes
1 answer
34k views

Ridiculously slow MacBook Pro

I have a MacBook Pro (I think mid 2012). About three months ago it started running really slow, so I renstalled the OS with a recovery partition. For a few weeks it ran very well with an overall very ...
user1291510's user avatar
6 votes
1 answer
8k views

How can I control (start/stop) applications and services that start up after reboot?

I have a Mac that is slow when using the internet, but other PCs on the same connection aren't as slow. I suspect there are too many AV scanners running concurrently, or there is some process that ...
makerofthings7's user avatar
5 votes
1 answer
220 views

Is it good to keep apps closed on iOS devices?

Is it better to keep apps closed (double tap home button, hold the icon, and exit the app), as much as possible on iOS devices? I know the more apps one has open, the more RAM, for example is used, ...
bassplayer7's user avatar
  • 14.1k
4 votes
3 answers
3k views

With Firefox Aurora, Mountain Lion hung - but the mouse still worked

I've just had my first Mountain Lion lockup. The screen was entirely frozen in place (I have seconds displayed on my clock in iStat Menu and even that wasn't moving) BUT the mouse still worked. I ...
Caesium's user avatar
  • 887
3 votes
1 answer
679 views

iPhone 7 is frozen and I can't turn it off

I went onto my iPhone 7 and tried to get into an app but couldn't I then tried swiping sideways along the screen but it wouldn't move. I tried turning it off but it got stuck on the sliding part and ...
Kitty Blackham's user avatar
2 votes
1 answer
710 views

WiFi Performance via Terminal

Is it possible to test the performance of a WiFi via the terminal? Basically, I want to check how good WiFi is in some spaces of my home to figure out where to place a access points. Can the ...
Narusan's user avatar
  • 259
1 vote
1 answer
370 views

How to trigger spinning wheel diagnostics report

I'm working on application that consume significant CPU time and memory under heavy load. my setup configuration is fusion VM that runs macOS Sierra 10.12.6. At some stage I get spinning wheel and ...
Zohar81's user avatar
  • 549
1 vote
2 answers
2k views

Broken battery - downgraded performance

I have old MacBook Pro that has a dead battery. It is not charging, and displays always 0% battery charge. OS X is downgrading performance when battery level is close to something about 5% or 10%. Is ...
gkucmierz's user avatar
  • 123
44 votes
3 answers
40k views

What are the differences between journaling HFS+ and non-journaling HFS+?

I'm about to format an external hard disk drive (HDD). What are the key differences between journaling HFS+ and non-journaling HFS+? Apart from the fact that one has journaling and the other does not,...
Jari Keinänen's user avatar
38 votes
7 answers
27k views

WindowServer is eating lots of CPU, can't work out why

2019 16" MBP running 10.15.4. WindowServer is eating a lot of CPU, idling at 10-20%-ish even with nothing much running. Fans are constantly going because of it. I've disabled transparency and stopped ...
Dan's user avatar
  • 561
36 votes
4 answers
14k views

How can I figure out which tab in Safari is using CPU?

I usually have several tabs open in Safari in the background, and sometimes I see it taking up an unusual amount of CPU (PluginProcess or WebProcess). How can I figure out which tab (or tabs) is ...
jtbandes's user avatar
  • 11.1k
22 votes
4 answers
1k views

Multi threaded CPU intensive task throttles CPU way before temperatures limits

I have written a very CPU intensive threaded task that works as expected on my 2012 MacBook Pro quad core. I turn it loose with 20 threads and the temperatures get up to about 100 °C as measured with ...
markatlnk's user avatar
  • 221
19 votes
2 answers
28k views

Computer slows when battery is low

My Macbook Pro running Mountain Lion slows down dramatically when the battery is below 4-5%. All the applications running are very slow to respond, and several have the "Application not responding" ...
pasawaya's user avatar
  • 2,306
18 votes
5 answers
2k views

Does the use of SSD give one a dramatic performance boost?

I use Mac book pro 15", and it's time to buy a new one. For HDD, now I see a new option of SSD, which is pretty expensive. I can expect shorter boot-up time and faster access of files, but I'm not ...
prosseek's user avatar
  • 5,684
15 votes
4 answers
12k views

Why is sudo taking way too long?

I recently updated to macOS Sierra 10.12.4 Beta (16E144f) and it might be what is causing sudo to delay up to 10 minutes as it's the most recent change I recall since this problem occurred. I have ...
Spencer Williams's user avatar
15 votes
6 answers
16k views

Alternative activity monitors for OS X?

I’m a bit intrigued by the new detailed activity monitors and progress indicators in Windows 8 (copying files, the task monitor, network activity, etc.) It got me thinking: surely there must be some ...
Daniel's user avatar
  • 3,888
14 votes
2 answers
1k views

How can I verify if Apple is slowing down my phone because of an old battery?

Apple has recently confirmed they're slowing down phones which have a battery that's too old. How can I verify if that's the case for my particular model? Is there an app that can tell me the current "...
JonathanReez's user avatar
  • 2,072
13 votes
2 answers
12k views

com.apple.hiservices-xpcservice results in frequent hangs and freezes in my mac

Update (2019): The issue still persits even in macOS Mojave, tried everything I could find, nothing seems to solve the issue as of yet! Problem: com.apple.hiservices-xpcservice hangs repeatedly ever ...
Sayan's user avatar
  • 2,259
13 votes
5 answers
1k views

What scenarios benefit from Mac OS X allowing apps to run when no document windows remain?

As a rule of thumb programs on Mac OS X stay running when you close all their document windows. This is the behavior I noticed in MacVim, VmWare Fusion, Chrome and host of other applications. I ...
Art's user avatar
  • 992
11 votes
2 answers
8k views

Tool for determining performance bottleneck

I am using my early 2011 MacBook Pro for iOS development, Photoshop work, and the like, and it is at times quite sluggish. Is there a tool that I can just run for a day, and then look at the ...
houbysoft's user avatar
  • 9,182
11 votes
4 answers
44k views

Finder slow/freeze under Mavericks

<rant>I wish I never upgraded to OS X 10.9, it is so buggy!! But the alternative to stick with the unpatched earlier version of OS X was not a solution! Anyway, so I am on this crappy Mavericks ...
Huygens's user avatar
  • 1,573
10 votes
2 answers
27k views

How to monitor CPU core usage?

I have a Macbook Pro 15" with the quad core i7. I am looking to see what if any performance decrease I could expect moving to a 13" Macbook Pro with a dual core i7. To that end I thought Activity ...
webworm's user avatar
  • 650
9 votes
2 answers
5k views

How to execute terminal command on energy efficient cores on M1 chip?

I want to run nodejs process on E cores, but when I run it I see that it uses P cores even if there is a 0.3 second task.
Dmitry Kozlov's user avatar
9 votes
2 answers
3k views

How to force a Terminal Command to run with the Performance Cores on Apple Silicon?

I recently had to reinstall the developer tools using xcode-select —install, but noticed that the install was completed with my efficiency cores rather than my performance cores. I know this because ...
Jacob Waters's user avatar
9 votes
5 answers
3k views

Does force closing apps have any benefit on iOS devices?

I've gotten mixed answers from various websites and people concerning this question, and I wanted to put it out there for all of you to answer once and for all. The question is, does force closing ...
Munesawagi's user avatar
  • 2,123
8 votes
2 answers
2k views

Why is Illustrator throttled to 2% speed when it's in the background?

I regularly run a .jsx script in Adobe Illustrator that saves a bunch of files in a particular format. while Illustrator is the active app, running the script on 5 files takes 23 seconds. When ...
Andy Swift's user avatar
  • 2,210