slow playback in premiere

Why do I get such crummy playback in Premiere? Do I have something set up wrong?

My computer struggled to do basic playback in Premiere so, when I built my next system, I looked for specs that should have allowed smooth 4K editing. But playback was still ****.

Figured it was my fault so, this time, I decided to let someone else build it.

I just purchased a workstation from Puget Systems.

• Intel Core Ultra 9 285K 3.7GHz 24 Core 36MB 125W
• 96GB  Kingston DDR5-5600
• MSI GeForce RTX 5080 INSPIRE 3X OC 16GB
• Windows 11

And … it struggles on playback.

I have three tracks:

• 1920*1080 MOV file exported from Animate.
• A single voice over track (.WAV or .MP3)
• A single music track (.WAV)

I’m playing back in a tiny little window (30%) and half resolution. Playback stutters. Sound frequently drops out altogether.

Do I have something set up wrong? How does this problem persist no matter how much RAM and horsepower I throw at it?

Thanks for any insights.