IDEA is very very slow


Hi guys, good evening.

I have a AMD FX-8350, 32 GB RAM, Fedora Core 20 development machine for work. It has a R9 290 video card.

I don't understand why the performance in IDEA is so slow. I have tried giving it 8, 12 gigabytes of RAM via the vm settings file, it only improves marginally.

I have disabled every single plugin except Scala, html and javascript which is what I'm working on.

It is still so painfully slow. I've turned off syntax highlighting and even used "mark as plaintext" (!!!!) and it still is slow!

Something is definitely wrong here.

I've decided to post only after I tried all the tricks found on Google for "intellij idea is slow", so I think I've covered the basics.....nothing worked.

IntelliJ IDEA 2016.2.4
Build #IU-162.2032.8, built on September 9, 2016

JRE: 1.8.0_112-release-b343 amd64
JVM: OpenJDK 64-Bit Server VM by JetBrains s.r.o


I'm using the Oracle VM, does this cause troubles with OpenJDK?

Linux kernel 3.19.8-100.fc20.x86_64 #1 SMP

x86_64 x86_64 x86_64 GNU/Linux

top - 22:32:41 up 1 day, 5:46, 11 users, load average: 2.75, 2.86, 2.69
Tasks: 323 total, 1 running, 322 sleeping, 0 stopped, 0 zombie
%Cpu(s): 5.4 us, 9.7 sy, 0.1 ni, 83.4 id, 0.0 wa, 0.0 hi, 1.3 si, 0.0 st


CPU is cool, system has less than 2 concurrent tasks avg for 8's definitely not a hardware issue.

Any tips appreciated. Thank you.


@Jfronseca, I'm a paying customer of IntelliJ, and have been for years, but it's stupid to think saying "Hey, it's running slow for me!" is a valid bug report.  It's not unreasonable for them to ask for a CPU snapshot or other information to diagnose the problem for you.  You're obviously a web developer.  How would you feel if a user reported, "Hey, the website sucks!" but didn't give you the proper information for you to actually do something about it?


Hello Serge, thank you for your reply.

If IDEA was a free / open source product I'd gladly help with the debugging.

But it's a commercial product and I've been a proud paying customer for a couple of years now, because it's a great product. But being a commercial solution means I need to fire it up and it needs to work.

I abandoned Eclipse years ago because of this exact same problem: it began to be unbearably slow. You guys had the fastest IDE on the market, the most stable one.

What happened? It's not about sending logs and debugging my installation, it's about JetBrains figuring out where it turned wrong, I think it was from 2014 to now or somewhere around there. In 2013 I clearly remember IDEA being lightning fast for me.

For larger HTML files it becomes impossible to work - open a tag and it sits there for seconds.... I'm using EMACS in parallel with IDEA for this....

So please take this as constructive criticism, whatever you guys added to 2016 and 2015 versions needs to be reviewed. I'm sorry I can't be sending you logs and helping out, I wish I could, but I think it's something structural you guys changed 3 to 4 years ago and you have a great team that can figure it out.


Jose Fonseca


@Jfronseca, you're downvoted because you're being a jerk, not because anyone thinks your request is illegitimate.  Instead of acting like a spoiled child slapping the face of the developers you're asking for support if you'd instead ask if there's another way to get help if you aren't able to submit such information I think you'd be met with far more positive results.  Scala works great in IntelliJ, so your issue is specific to you.  This is why they need your assistance...not because we are all colluding together to make your life suck, but because they genuinely need more to go on than, "this is slow for me".  I'm sure for them, like me, they aren't seeing the same problem you are.


> It's been 8 months since I opened this case

You posted a message to a public forum and didn't provide the information we asked for that could help us to investigate and fix it. Proper cases are opened via support at or at YouTrack at If you provide the data we ask for, our developers will look into the problem and see what can be done to address it or the support team will suggest some setting/workaround.


CPU snapshots do not contain any sensitive information about your projects. The data recorded is only about IDE itself.


You don't debug it, you spend 1-5 minutes to provide the data and we investigate, debug and hopefully fix it. That is not much harder than posting to a forum.


Well, I'm glad I could be of assistance. :)


I absolutely agree with Jfonseca 

Especially Idea 2017 is super slow even compared with Idea 2016 version.

Slow typing, slow startup, slow compiling and debugging. I like a lot jetbrains products and the company I work for also prefer to work with jetbrains products but in recent years it is getting worse and worse in speed. I appreciate the new functionality/frameworks support etc.. that was added in recent years but if it is slow, nobody will be able to use them.

Please jetbrains, investigate the performance issues more then just adding new features


> I appreciate the need to reproduce the problem but if JetBrains developers don't see the problem then I would suggest there is a big gap between their usage and that of the general development community.

That is true, there are thousands of possible configurations that potentially can cause issues and that will be never used locally at JetBrains. That is why we have a public issue tracker and the instructions how these problems can be properly reported in order to be fixed.

It's also a matter of hardware and software configuration. Certain combinations can cause problems (like 4K external display on Mac with non-native resolution). We don't have all the possible hardware and software configurations in the world to isolate the issues locally.

Getting a CPU snapshot and reporting a problem at is a matter of 5 minutes.


Serge, I have a clean installation of Mac OS X running Java HotSpot 1.8.0_121. It is the latest Macbook Pro 2016 with highest specs.

I just increased the memory in JVM options

# custom IntelliJ IDEA VM options


What can be wrong?


Appreciate your input, however I'm not sure what exactly to escalate and to whom. As a developer, you should understand that in order for the problem to be fixed, it has to be either reproduced or the data needed to isolate it is provided from the system where this problem can be reproduced. Put yourself on the place of JetBrains developers. User complains about poor performance, but on your system and with your projects everything works just fine. User doesn't provide you any data about this performance problem. How would you fix it?


> Personally I installed the latest version of IntelliJ IDEA from the official download page and imported the code base for my client's project.  There is one Gradle java project with six modules with an average of 100 classes in each and associated dependencies.  This is not an unusually large project in my experience.  I have not modified the configured plugins in any way.

How do we know that the problem you have is not something that is already reported and being worked on? How do we know that it's not already fixed in the master branch? Maybe there is already or workaround or a solution for your problem, but we can't help you because we don't know which specific problem you have unless you provide the requested data.


> Who to escalate to: People in JetBrains that would be concerned about these complaints.  I would suggest for you to speak to whoever you report to as a starting point.  You should alert them that there is a general dissatisfaction with the product.  You should *not* keep this to yourself in a personal battle between you and the customers in this thread.

The first questions from any developer would be: Is there a CPU snapshot available? Is there a reproducible test case? Until this information is provided, there is nothing to escalate.


Wrong JVM options is just one of the hundreds of possible cases. To tell what's the problem in your specific case we need to analyze the CPU snapshot recorded on your system. We can waste more time guessing or we can check the snapshot and suggest something. Please contact support with the requested file attached via or file a performance problem at

Blindly increasing the heap size is also not always good since it can increase GC pauses.


Clintomed, JetBrains addresses many performance problems if they are reported properly. For this specific thread the original reporter didn't provide us any data that would help to understand and fix it. It also doesn't mean that your problem is the same as the problem of the topic starter.

So, to get your specific problem resolved, please submit a performance problem report at with the CPU snapshot attached (

This is the only way to report your performance problems and the only way to get them addressed. I'm closing this thread for further comments. If you need help, please submit a ticket to support or report the issue directly to YouTrack. Thank you for understanding.

P.S. Hello Reddit!


Our products can fully utilize multiple cores when performing indexing. So, 8 cores would probably provide better indexing times (considering your I/O subsystem would not be a bottleneck, so fast SSD is also recommended).


There is nothing wrong with utilizing 600% CPU on a multicore system. It either takes longer time and utilizes less CPU, or it uses all the available resources and performs indexing faster.


> How I would fix it: As part of development or testing processes, simulate large projects with significant dependencies to external libraries, applications/processes running within IntelliJ in debug mode, and then run a profiler to see where the bottle necks may be.  I would be astounded if this isn't being done in some way already but if you are unable to replicate the problems then like I said before, there is a big disconnect between what you do internally and what the rest of us do.

Of course we do test IntelliJ IDEA with large open source projects, but there would be always bottlenecks that are specific only to some projects, hardware and software configurations that cannot be tested and reproduced locally.


Every performance problem is unique, it's completely normal for a paying customer to submit a CPU snapshot so that the problem can be investigated and fixed. No product is perfect.

You are welcome to submit a ticket to support here if you are more comfortable with that rather than using an issue tracker.


All the developers are aware that the product can have performance problems. There are dozens of performance problems reported and fixed at every month.


My anti-virus software has On-Access scan. It helps when it is disabled.

Also, changing max memory size for the ideaj process is something to be considered.


I am beginning to understand the other users disappointment and anger. As time drags on the problem almost seems to get worse. Is JetBrains going to address these issues? If not, what are we paying for?


Product is the slowest IDE I've ever used, on multiple machines. As we speak it has redlined at 600% CPU for twenty minutes, after restarting. this i crazy. switching to VSCode with proper plugins.


We can help only if you provide a CPU snapshot:

There could be some customized JVM option you are using that affects the performance or it could be a hundred of other possible cases. We can't guess why it's slow for you unless you provide the requested data. Hint: no, it's not slow for all and in some cases it's a problem with user environment or JVM configuration.


> Please jetbrains, investigate the performance issues more then just adding new features

We fix dozens of performance problems per month, check this link (it's just a fraction of the performance problems fixed since there are also tickets in other projects that are part of IntelliJ IDEA codebase).



I'm with Jfonseca and xvitcoder and everybody else that is complaining about performance.  It's such a common overarching problem across the product that is rendering it close to useless.

Asking for a CPU snapshot for every posting in this thread is equally useless.  It's blindingly obvious that the product has become close to atrocious when you type into a code editor and there is a delay of several seconds before it displays the characters on the screen.

If you want to provide any sort of value to clients I suggest you escalate this to whoever in the JetBrains hierarchy has the brain (no pun intended) to stop being in denial and fix the damn thing or start losing clients very rapidly.

I challenge you to not respond with a comment about needing the CPU snapshot but rather that the problems are being escalated as a matter of urgency with a view to releasing the fixes ASAP. 



@Matt Hicks I am glad that you are having success with the Scala plug in. Surely as a programmer you understand that there are a lot of indeterminate reasons why users in different environments would have different problems.

I think I got a lot of my issues fixed by upgrading to 2017.2 EAP and getting the latest nightly Scala Plugin build. 


I understood that part, Serge. Thank you.


@Clintomed, I don't know what you mean by "barely usable".  I program almost exclusively in Scala in IntelliJ and apart from some complaints about the indexing (which is actually what led me to this page) performance on one specific machine, the Scala plugin is fantastic and fast.