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Questions tagged [performance]

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

142
votes
8answers
105k 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 ...
127
votes
10answers
143k 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. ...
70
votes
5answers
20k views

A tech from MacKeeper wishes access to my computer for licensing and activation. Is this a scam?

I paid for a version of MacKeeper which may be a mistake. Their tech wants me to allow them to access my computer as in have access to my desktop files, etc. They say it is to fully license and ...
51
votes
13answers
56k 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/...
50
votes
10answers
36k 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, ...
49
votes
9answers
56k 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, ...
41
votes
3answers
32k 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,...
36
votes
5answers
6k views

Do computers slow down as they age?

I have an eMac I bought in 2004. I just used the system restore CD to re-install Panther, iLife '04, Internet Explorer for Mac(!), etc. I don't have any timed specs from "back then", so I can't answer ...
28
votes
4answers
5k 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 ...
27
votes
5answers
1k views

Is there any way to speed up my iPhone 3G since upgrading to iOS4

I have recently upgraded my iPhone 3G to iOS4 and there is some noticeable performance issues will some of the basic tasks (text messaging, loading application, etc.) I have restarted my iPhone and ...
24
votes
4answers
18k 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 ...
21
votes
4answers
512 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 ...
20
votes
12answers
56k views

Will Mountain Lion make an older computer run faster or slower?

Performance/responsiveness is a common concern with new software, especially on older machines. In general, upgrading from Snow Leopard (10.6) to Lion (10.7) wasn't too bad, but now Mountain Lion (10....
18
votes
5answers
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 ...
17
votes
4answers
20k views

How can I speed up SD card writing speed (using /dev/disk*) on a MacBook Pro?

I've been installing some linux distributions onto an SD card from my MacBook, although they take over an hour to transfer a few hundred MB (using dd and /dev/disk1). If you look at the above output ...
16
votes
2answers
8k views

sharedfilelistd and distnoted hog CPU

I understand from my findings on the topic that sharedfilelistd is an "agent that is used by applications to read/modify recent documents/servers/hosts" and distnoted a "distributed notification ...
15
votes
3answers
13k views

How would enabling FileVault alter my system and TM performance?

What are the pros and cons, performance-wise, of enabling and using FileVault? Is there any at all, or does it slow a computer down significantly or on the contrary speed it up? Also, what effect will ...
15
votes
1answer
56k views

How to identify CPU and memory usage per process on iPhone?

There are many common apps available to show total system RAM usage and free. However, my understanding is only a jailbroken phone has access to the APIs to access PER PROCESS memory usage on iOS. ...
15
votes
2answers
17k 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 ...
15
votes
2answers
19k 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" ...
15
votes
2answers
67k views

Kernel_task using 300% CPU time, high fan speed and slow computer in MacBook Pro [duplicate]

My MacBook Pro has become slow lately. Activity monitor shows kernel task is using around 300% CPU. The fan is always on at high speed. Below are the details of my computer: Macbook Pro 13-inch, Mid ...
14
votes
2answers
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 "...
14
votes
5answers
24k views

Using FaceTime without the video

I have a first generation MacBook Air that heats up a lot when playing videos, and almost grinds to a halt after a few minutes of playback. Is there a way I could turn off the video during FaceTime ...
14
votes
3answers
6k views

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....
13
votes
6answers
13k 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 ...
13
votes
2answers
6k views

What does FreeMemory actually do?

There's a highly-rated app on the Mac App Store called FreeMemory. It claims to be able to "increase your free memory with a simple click." Although it's free right now, I believe it normally goes ...
13
votes
3answers
8k views

How can I diagnose or fix the CalendarAgent occupying a whole CPU on Mountain Lion?

Since I upgraded to Mountain Lion from Lion I see the CalendarAgent process occupying a large amount of 1 CPU on my late-2008 MacBook Pro. To fix this (as suggested by a Google result) I tried ...
12
votes
5answers
6k views

How to slow down clock speed of processor

I recently bought a new MacBook Pro which sometimes goes too fast. I frequently program for Mathematica, and on my old 2007 MacBook Pro I usually got a feeling for inefficient code when it runs ...
12
votes
5answers
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 ...
12
votes
5answers
7k 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 ...
12
votes
1answer
8k views

How do I disable/configure macOS Sierra's auto throttling of the CPU for processor intensive tasks

I'm using an iMac (late 2015) with an Intel core i7 (quad core) 4GHz CPU with 32GB ram and a 3TB Fusion Drive. I'm a software developer working on a huge codebase that used to take about 30 minutes to ...
12
votes
1answer
34k views

Monitor GPU performance on OSX

Is there an application or tool that can monitor GPU performance on OS X? Specifically I would like to see the current speed/utilization and temperature of the integrated NVIDIA chip. For Windows, ...
11
votes
5answers
8k views

How can I simulate having a slow CPU?

I am almost done coding my webapp-game. It runs on all modern browsers. However, I want to establish some minimum requirements for it. Thus, I need a slow Mac. However, I don't have access to a slow ...
11
votes
5answers
6k views

Should you format your Mac?

Back in my Windows days, I used to fully format my PC once a year or so, to start fresh and get rid of some of the slowdowns. It helped. Would you recommend the same for Macs? What's the recommended ...
11
votes
1answer
922 views

Why does Dashlane use so many ports?

I use Dashlane to store passwords, and I like it, but there's one problem I've had with it. I use Activity Monitor to see what's going on, and something strange has been happening with Dashlane lately....
11
votes
4answers
12k views

What is 'symptomsd" and why is it at times using 60% of my iMac's CPU?

There is a system process on my iMac running El Capitan called "symptomsd" that has been consistently bouncing back and forth between about 20% to 60% of the CPU resource on my iMac. It is running ...
10
votes
3answers
6k views

How can I have 1805 threads when I only have 4 virtual CPUs?

I was wondering if someone could explain to me how in my Activity Monitor it says that I currently have 1805 threads But I only have 4 virtual cores on my computer (which means that I should only be ...
10
votes
2answers
2k views

ZSH paste from the clipboard a command takes a few second to be write in the terminal

When I copy from the clipboard a long string command in my iTerm, the terminal freeze for seconds. for example, if I copy the following test and I paste in my iTerm console: echo 'test test test ...
10
votes
5answers
32k 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 ...
10
votes
4answers
3k views

What has changed Finder list view in Lion to make “Calculate all sizes” exponentially faster?

Since way before Mac OS X came on the scene, we have been able to ask the Finder to Calculate all sizes in order to determine the sum total of readable file size space contained in each folder for the ...
10
votes
2answers
6k 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 ...
9
votes
3answers
16k views

Can the iPad / iPad 2 handle iOS 6?

I've heard anecdotal evidence of iOS 6 seriously impairing the performance of the iPhone 4 (and had a poor personal experience with it on iOS 5). I was wondering if anyone has had any problems ...
9
votes
1answer
697 views

My MacBook Pro, High Sierra downloaded 13G last night while asleep

The system was presumably closed at my workplace. How can I find why ? Some light on those 13Gb ? How Activity Monitor finds those numbers ? I will be glad to provide more information while the ...
9
votes
2answers
530 views

How can I tell if a directory has APFS Fast Directory Sizing enabled?

Apple's technical documentation in the Apple File System Guide describes that some directories like /tmp are not good candidates for the fast directory sizing feature. Fast directory sizing works ...
8
votes
8answers
11k views

Yosemite: Accessibility zoom + multiple monitors = poor performance

Ever since upgrading to Yosemite, the accessibility zoom feature is unusable when connected to an external monitor. Steps to reproduce: Enable Zoom in System Preferences - Accessibility. Connect an ...
8
votes
5answers
24k views

quicklookd and revisiond eating my CPU

I'm observing regular and abnormal CPU usage on my macbook pro. quicklookd in par with revisiond are eating together over of 50%. It drains my battery significantly and makes the whole machine hot. I'...
8
votes
5answers
2k 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 ...
8
votes
2answers
45k 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 ...
8
votes
1answer
12k views

How to find out which Safari tab is using massive memory?

As described in my other question, Safari on OS X 10.6. is causing me massive problems (with my way of working like having many tabs in Safari open for a long time). I just realized that after ...
8
votes
2answers
532 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 ...