Mike-71

Is this really the recommended way? As I experience a lot more crashes, when moving the slider to more than 70-75ish percent. And the more other apps I open, the worse. Whereas other design apps don't crash if set them to 100% RAM usage as they seem to set it free again when running in background or play nicely together with other apps in the background using my RAM.
I only have trouble with Affinity apps when they are allowed to claim up to 100% RAM.

Hi @Mike-71,
Welcome to the Affinity forums
Firstly I'd recommend setting your RAM Limit (the first slider in the dialog) to 16384MB, so that the app can use all 16GB of your RAM when required.
As Walt has mentioned above, this feature is still in an early phase of infancy and although it has the potential to speed up rendering drastically, it can also causes a few crashes currently.
If you are able to enable this and wish to try it, please make sure you're using the most up to date driver for your GPU from nVidia directly before enabling the option for the best results.
I also recommend checking out the following FAQ regarding the other options here and the best performance from the app -
I hope this helps

Welcome to the Serif Affinity forums.
Given the number of reported problems, perhaps you shouldn't. But it may be worth experimenting with. It's up to you. The performance without it should be identical to what you had in 1.8.
However, it is activated by default in 1.9 when you have an appropriate Windows release and an appropriate GPU. So, if it's not enabled, and you did not specifically disable it, you probably cannot enable it.