# Launch settings

It is possible to personalise the launch settings of Ancestris.

In general, you should not need to set or modify them.

However, in some specific circumstances, you may want to tweak them a bit.

It is as simple as editing the line in the Ancestris configuration file. Please refer to the [location of the configuration file page](https://docs.ancestris.org/books/user-guide/page/software-files-and-user-settings-files#bkmrk-the-configuration-fi "Where are the configuration files ?") to know where it is located.

## Set memory size for large genealogies

Ancestris works perfectly fine with genealogies of several dozens or thousands of individuals.

You can get Ancestris to work with several genealogies at the same time.

We recommend a 4 GB memory for very large genealogies.

<p class="callout success">Ancestris can open and manage a simple genealogy of 600,000 individuals.</p>

---

For very large genealogies, we recommend that you change Ancestris's startup parameters to increase maximum memory size for Java.

- Parameter to change: `-J-Xmx` to 8GB for instance.

```
default_options="-J-Xmx8g --laf Nimbus --branding ancestris --locale fr -J-Xms96m"
```

We also recommend, if needed, to reboot your device and to only start Ancestris and nothing else, so that all memory available will be allocated to Ancestris.

## Set default language

The default language can be set in Ancestris preferences.

It can also be initialised to a language of your choice using the launch setting.

- Parameter to change: `--locale` to the 2-digit-language code. Example : "en".

```
default_options="-J-Xmx1g --laf Nimbus --branding ancestris --locale en -J-Xms96m"
```

## Set default look and feel

The default look and feel can be set in Ancestris preferences.

It can also be initialised to a look and feel of your choice using the launch setting.

- Parameter to change: `--laf` to the look-and-feel name provided in Ancestris preferences.

```
default_options="-J-Xmx1g --laf Nimbus --branding ancestris --locale en -J-Xms96m"
```

For the standard look and feel, remove the parameter from the line.

## Set default icon size

In very rare circumstances, if you modify the default size of the fonts and icons on your computer or use a very large screen, Ancestris might display its icons in too small a size.

It is possible to increase the aspects of the icons with Ancestris using the following method but only with Java 11.

- Parameter to change: `-J-Dsun.java2d.uiScale=2`

```
default_options="-J-Xmx1g --laf Nimbus --branding ancestris --locale en -J-Xms96m -J-Dsun.java2d.uiScale=2"
```

### Windows specific instructions

Another way to force icon size on Windows with Java version 8 is the following.

<div id="bkmrk-right-click-ancestri">Right-click `ancestris.exe` or `ancestris64.exe`, select **Properties** and choose the **Compatibility** tab.</div><div id="bkmrk--0"><div>  
</div></div>[![User_settings_icon1.png](https://docs.ancestris.org/uploads/images/gallery/2020-06/scaled-1680-/User_settings_icon1.png)](https://docs.ancestris.org/uploads/images/gallery/2020-06/User_settings_icon1.png)

<div id="bkmrk-click-on-change-high"><div><div>Click on **Change high DPI settings**.</div><div><div>  
</div><div>  
</div></div></div></div>[![User_settings_icon2.png](https://docs.ancestris.org/uploads/images/gallery/2020-06/scaled-1680-/User_settings_icon2.png)](https://docs.ancestris.org/uploads/images/gallery/2020-06/User_settings_icon2.png)

<div id="bkmrk-set-the-choice-to-sy"><div><div>  
<div>  
</div><div>Set the choice to **System**, validate with OK and then restart Ancestris.</div></div></div></div>