Knowledgebase:
Slow download speed
Posted by pspzockerscene psp, Last modified by pspzockerscene psp on 23 June 2020 03:00 PM

Slow download speed

This is a troubleshooting guide about download speed.
In general, bad download speed is not any kind of error of JDownloader but more a user error (bad configuration) or e.g. the website you're trying to download from has speed issues.

This guide will try to help you to find out why your download speed is bad and possibly find a solution.

First we're going through possible JDownloader configuration failures, then through other problem sources.

In all cases, you should always compare the speed in JDownloader vs. the speed in browser by downloading the SAME file over the SAME service with the SAME account(s).
If yopu are using a proxy/VPN in JDownloader, make sure you're using that inm your browser too if you want to get meaningful test results.
In a lot of cases you will notice that the speed you get via browser is the same you get via JD which would indicate server issues/slowdowns of the service you are trying to download from.

Slow download speed when downloading from video/streaming websites?
Some video streaming sites have bandwidth limits in place - especially those that do not provide any comfortable ways to download their content e.g. a download button on their website.
They're basically limiting the max. download speed somewhere near the max. bandwidth of the currently streamed video quality.
This ensures that users who stream the video can do so without any lag and prevents bandwidth bottlenecks caused by users who are downloading streaming content.

Slow download speed because of too low connection settings?
Check your connection settings first!

Slow https(SSL) and high CPU usage during download?
Modern SSL Ciphers can result in very high CPU usage and also slow speed - especially on older/single-core ARM CPUs commonly e.g. used in older/smaller Synology NAS systems.

Most likely the CPU/Environment doesn't support hardware accelerated encryption! Especially modern AES GCM Cipher also suffers from known performance issues in older Java versions.

If you have an Intel/AMD CPU, you can experiment with newer Java versions (eg recent Java 1.8 or latest LTS version).
All in all there isn't much you can do but for some plugins, you will find a workaround setting which lets you disable https for that particular service.
See Settings --> Plugins --> yourservice.com --> ENABLE "Prefer http over https" (or similar) or DISABLE "Use SSL/https" (or similar)
Support forum thread regarding Synology SSL issues

1. Did you enable a speed-limit by mistake in JD? (Speedgraph does show a red line for enabled speed-limit)
Picture of speedgraph in the top right corner with the red "limit" line, visible while downloads are running:

- Make sure that the pause button is disabled: It is right next to the "start downloads" ["play button"] button
- Make sure that you did not enable a speed limit by mistake: See Speed limit and Pause mode settings

2. Did you forget to add your premium account?
If you own a premium account for a certain service, you should add it under Settings --> Account Manager --> Add

3. Did you disable your premium account by mistake or is there an error-state on it?
If you've added a premium account for a service, make sure it is activated under Settings --> Account Manager
Also check for temporary errors (= account gets displayed in color yellow) or permanent errors like invalid password which would display the account with a red background.

4. Did you globally disable premium by mistake?
In the main toolbar there is a symbol with a yellow lock.
This globally enables/disables all premium accounts - make sure it is enabled!
Screenshot:

5. Does your firewall/AV scanner block JDownloader?
Make sure that your firewall does not block JDownloader in any way.
You can check this e.g. by completely disabling it - deactivating it might not always turn it off completely.
If you are using the firewall of your OS only however, it is enough to temporarily disable it for testing.

6. Do you use a VPN for downloading?
VPNs can become a bottleneck when downloading.
Turn it off and try again!

7. Does your ISP have issues?
There are various speed test websites out there - grab one and test the max. speed you're currently getting from your ISP.
Your issues might as well be caused by routing issues!

8. Does the service you want to download from have server/speed issues?
Search the web to find out if there are currently any reported issues with the service you're trying to download from.
In this case you would definitly have to contact the providers' support - the JDownloader support will be unable to help solving issues which 3rd party services are having!

9. Is your issue connected to the device you're currently using e.g. bad network configuration?
Test the same file via the same account with the same proxy/VPN on other devices in your network to find out if your issue is e.g. related to the device you are currently using.

10. Does the issue only happen with a specified file?
Check if you can reproduce your issue no matter which file you are downloading.
In some cases, some files might be stored on overloaded servers so out of many files you may try to download, only single files have a slower download speed.

Only contact our support regarding speed issues, if:
- Speed in browser- and JDownloader are clearly different
- You've gone through this troubleshooting guide and were unable to identify any other causes of your speed issues other than JDownloader



Attachments 
 
 downloads_quicksettings_speedlimit.png (35.36 KB)
 toolbar_globally_enable_disable_premium.png (17.90 KB)
 speedgraph_with_speedlimit.png (3.03 KB)
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