After Effects not playing in real time preview

I will try the solutions presented. Thank you very much

Something else to try:  If the duration of your Compositions are on the longer side, and that would be anywhere from 30 seconds to a minute to five minutes or more, set the Work Area to a shorter duration for when you Preview. Try a five second or a 10 second range, let After Effects cache that time span (you'll see green above it), and then play the preview.  If set to loop, the first play through may show as not being real time, but by the second or third loop it should play in real time.  You can click and drag from the middle of the Work Area to slide it down the Time Ruler to preview other area at the same duration. 

If you cannot get real-time previews at all, condition rendering previews to a video format that you are confident that your computer can play smoothly in VLC Player, Windows Media Player, Apple QuickTime Player.  But also reply with details about your computer specifications, and the settings that you're working at inside of after effects because, as I'm sure you're aware, it's best to be able to play your previews in real time directly inside of After Effects.

I am not sure about your environment. I would recommend that you set the cache disk on M.2 Gen 4 SSD separately if you can add one.

Thanks for writing in, sabine_4280.

After Effects preview works differently than an NLE like Premiere Pro. After Effects needs to store cache (indicated by the green line) before showing the preview in real time. So, the part of the timeline that is green should be previewed in real time.

Hope it helps. Let me know if there are any other questions.