<p>Cura has and/or had a memory leak (or some other similar phenomenon) that occurs if you leave it running for a long time.  I have left Cura running for days or a week or three and eventually ran into a similar problem.  One could infer that you've left Cura running for a month, though it's not clear in your question.</p>

<p>I update Cura a few weeks ago (maybe a couple months) and noticed that it had a substantially smaller memory footprint, so that tells me they are working on memory management.</p>

<p>Looking in the <a href="https://ultimaker.com/en/products/ultimaker-cura-software/release-notes" rel="nofollow noreferrer">release notes</a>, you can see that 2 versions ago they implemented analytics, which is possibly a reason for the poor performance.  You'll also notice a lot of new features and bugs fixed int hat version.  That means a lot of work went into it.  Coupled with the short time to another release, and I think they're working on  fixing things.</p>

<p>For a more precise answer, include details and specs about your PC, internet connection, mother's maiden name, SSN, etc.  I'm kidding about the last 2, but it is probably a PC or software problem that you're running into.</p>

CC BY-SA 4.0
2018-09-21T23:17:18.293Z
Ah! That could definitely explain it; I do leave Cura open for extended periods of time, sometimes as long as a week. However, a memory leak would be odd, seeing as how my system isn't at capacity when this happens.
ifconfig
CC BY-SA 4.0
2018-09-21T23:21:40.173Z
Cura installs itself as a 64 bit program, but it's less than 400k and yet consumes ~250mb on startup.  It has more DLLs than you can shake an army of sticks at.  Who knows their bit depth, memory management, etc.  It looks like there's some python in there too, so the python interpretor or one of those scripts might be causing problems.  There are a lot of opportunities for failure in all of those parts and pieces of code, including cascading failure.
YetAnotherRandomUser
CC BY-SA 4.0
2018-09-22T01:13:06.780Z
I'm not too familiar with the ramifications of what you just mentioned. How does Cura being 64-bit impact its likelihood to have memory leaks?
ifconfig
CC BY-SA 4.0
2018-09-22T10:36:53.803Z
64 bit means it can use more than a few GB of RAM (the limit is 3-4gb).  Importantly, all of that first few GB is reserved for 32 bit apps, so they have to play nice with each other (unless newer OS's fix that).  I notice 32 bit Firefox become extremely sluggish between 2 and 3GB of RAM usage, but restarting it fixes it.  You said that Cura isn't standing out for memory usage, but didn't provide numbers.  When I had problems with Cura, it was consuming lots more RAM than normal, indicating a memory leak, or some other memory-related problem.
YetAnotherRandomUser
CC BY-SA 4.0
2018-09-22T18:42:02.400Z
Oh, Cura never uses more than 500MB of RAM. Question updated with a screenshot of tskmgr.
ifconfig
CC BY-SA 4.0
2018-09-21T23:09:23.690Z
2018-09-21T23:09:23.690Z
YetAnotherRandomUser
<p>I've been using Cura on my computer for a while now, (<em>at least a month</em>) but all of a sudden the entire interface has become noticeably sluggish. Whenever I scroll through the profile parameters list or the settings visibility dialog, the list lags and doesn't fully appear.</p>

<p>I'm at a loss to explain why this is happening.</p>

<p><a href="https://i.sstatic.net/5Op8h.gif" rel="nofollow noreferrer"><img src="https://i.sstatic.net/5Op8h.gif" alt="Example"></a></p>

<p><a href="https://i.sstatic.net/JBNyS.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/JBNyS.png" alt="tskmgr"></a></p>

CC BY-SA 4.0
2018-09-18T00:13:03.353Z
Not the machine itself? Have you looked at your performance monitor to see if there might be something in the background? Have you tried reloading Cura?
Pᴀᴜʟsᴛᴇʀ2
CC BY-SA 4.0
2018-09-18T00:19:26.443Z
Surprisingly, @Pᴀᴜʟsᴛᴇʀ2, there isn't anything in Tskmgr (_or Performance Monitor_) to suggest there is a bottleneck outside of Cura. Plenty of free CPU cycles, an abundance of free RAM, etc.
ifconfig
CC BY-SA 4.0
2018-09-18T07:08:17.277Z
Wrong settings on the video or your video driver has changed. Another thing is over heat on your CPU or chipset Or some sectors on your hard drive are damaged. :p 21 years repairing PC's
Fernando Baltazar
CC BY-SA 4.0
2018-09-18T07:47:46.173Z
Uh... a) what such driver settings? b) doubt it's CPU temp, not thermal throttling c) SSD, not HDD.
ifconfig
CC BY-SA 4.0
2018-09-18T14:56:01.520Z
does any other GUI-based tool show sluggishness?   Have you tried clearing out various log and preference files related to Cura?  Did you verify you don't accidentally have more than one instance of Cura running?
Carl Witthoft
CC BY-SA 4.0
2018-09-18T15:09:59.037Z
@CarlWitthoft No. Cura is the only one acting this way.
ifconfig
<ultimaker-cura>
Cura acting REALLY sluggish all of a sudden
ifconfig
# Cura acting REALLY sluggish all of a sudden

(Asked by: username_0 on 2018-09-17)

I've been using Cura on my computer for a while now, (*at least a month*) but all of a sudden the entire interface has become noticeably sluggish. Whenever I scroll through the profile parameters list or the settings visibility dialog, the list lags and doesn't fully appear.

I'm at a loss to explain why this is happening.

[![Example](https://i.sstatic.net/5Op8h.gif)](https://i.sstatic.net/5Op8h.gif)

[![tskmgr](https://i.sstatic.net/JBNyS.png)](https://i.sstatic.net/JBNyS.png)

**Tags:** ultimaker-cura
> **Comments:**
> **username_1**: Not the machine itself? Have you looked at your performance monitor to see if there might be something in the background? Have you tried reloading Cura?  
> **username_0**: Surprisingly, @Pᴀᴜʟsᴛᴇʀ2, there isn't anything in Tskmgr (_or Performance Monitor_) to suggest there is a bottleneck outside of Cura. Plenty of free CPU cycles, an abundance of free RAM, etc.  
> **username_2**: Wrong settings on the video or your video driver has changed. Another thing is over heat on your CPU or chipset Or some sectors on your hard drive are damaged. :p 21 years repairing PC's  
> **username_0**: Uh... a) what such driver settings? b) doubt it's CPU temp, not thermal throttling c) SSD, not HDD.  
> **username_3**: does any other GUI-based tool show sluggishness?   Have you tried clearing out various log and preference files related to Cura?  Did you verify you don't accidentally have more than one instance of Cura running?  
> **username_0**: @CarlWitthoft No. Cura is the only one acting this way.  

---

## 1 answers

### Answer by username_4 on 2018-09-21. Score: 1

Cura has and/or had a memory leak (or some other similar phenomenon) that occurs if you leave it running for a long time. I have left Cura running for days or a week or three and eventually ran into a similar problem. One could infer that you've left Cura running for a month, though it's not clear in your question.

I update Cura a few weeks ago (maybe a couple months) and noticed that it had a substantially smaller memory footprint, so that tells me they are working on memory management.

Looking in the [release notes](https://ultimaker.com/en/products/ultimaker-cura-software/release-notes), you can see that 2 versions ago they implemented analytics, which is possibly a reason for the poor performance. You'll also notice a lot of new features and bugs fixed int hat version. That means a lot of work went into it. Coupled with the short time to another release, and I think they're working on fixing things.

For a more precise answer, include details and specs about your PC, internet connection, mother's maiden name, SSN, etc. I'm kidding about the last 2, but it is probably a PC or software problem that you're running into.

> **Comments:**
> **username_0**: Ah! That could definitely explain it; I do leave Cura open for extended periods of time, sometimes as long as a week. However, a memory leak would be odd, seeing as how my system isn't at capacity when this happens.  
> **username_4**: Cura installs itself as a 64 bit program, but it's less than 400k and yet consumes ~250mb on startup.  It has more DLLs than you can shake an army of sticks at.  Who knows their bit depth, memory management, etc.  It looks like there's some python in there too, so the python interpretor or one of those scripts might be causing problems.  There are a lot of opportunities for failure in all of those parts and pieces of code, including cascading failure.  
> **username_0**: I'm not too familiar with the ramifications of what you just mentioned. How does Cura being 64-bit impact its likelihood to have memory leaks?  
> **username_4**: 64 bit means it can use more than a few GB of RAM (the limit is 3-4gb).  Importantly, all of that first few GB is reserved for 32 bit apps, so they have to play nice with each other (unless newer OS's fix that).  I notice 32 bit Firefox become extremely sluggish between 2 and 3GB of RAM usage, but restarting it fixes it.  You said that Cura isn't standing out for memory usage, but didn't provide numbers.  When I had problems with Cura, it was consuming lots more RAM than normal, indicating a memory leak, or some other memory-related problem.  
> **username_0**: Oh, Cura never uses more than 500MB of RAM. Question updated with a screenshot of tskmgr.  

---

