user26247: I have the preview resolution set to quarter, frame skip set to 5 and yet After Effects is previewing at full resolution constantly. I have tried changing the settings through the sidebar and the bar under the preview.
I have purged the RAM, cache, etc. several times and even re-opening the program does not help.
The preview is indeed set to 'Adaptive resolution'. This is making the preview playback impossible since my footage is 4K. 

user26252: Quarter of 4K is still 1080. Depending on your rig it still might chug thru playback. I would look into proxies as they are pretty quick to set up and would drastically improve workability.

26247: <p><a href="https://i.stack.imgur.com/InGmu.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/InGmu.jpg" alt="enter image description here"></a>I have the preview resolution set to quarter, frame skip set to 5 and yet After Effects is previewing at full resolution constantly. I have tried changing the settings through the sidebar and the bar under the preview.</p>

<p>I have purged the RAM, cache, etc. several times and even re-opening the program does not help.</p>

<p>The preview is indeed set to 'Adaptive resolution'. This is making the preview playback impossible since my footage is 4K. </p>
 26252: <p>Quarter of 4K is still 1080. Depending on your rig it still might chug thru playback. I would look into proxies as they are pretty quick to set up and would drastically improve workability.</p>
