Playback frame rate drop, but audio is fine?

[Average Dave]

I've rendered 7 mins of footage, but there is a section that has 1 videoclip overlaying another as I intend it to, but when I playback the project, that particular section becomes blurry and shows major frame rate drop whilst the audio is perfectly fine.

After going through the troubleshooting, nothing has worked to bring that section up to the same or similar quality as all the other footage. Does anyone have any advice or is experiencing similar problems??

(The attached image: where the green bars are is where I am experiencing problems. All other footage is at 1080p resolution and around 50fps.)

[Bill Sprague]

In the Edit > Preferences > General tab there is a setting for Timeline render quality.  Try changing it.  

It may be that your computer is doing the best it can to provide a real time edit preview.  The final output takes more time to process and may be fine.  Use the work area bars and output the troublesome section and see what it looks like.  

[Average Dave]

Thank you for your reply! My computer does struggle a bit as it only meets the minimum specification so I'm giessing that's the reason for the lag spikes. The final exported video is completely fine, so it's just the preview that has issues - I can get used to it though.

[Amit Kumar Gupta]

It depends on the machine configuration and project complexity. Please share your CPU & RAM details and effects/transitions used in the app.

You should not see this problem in the exported video 

[Average Dave]

I only just meet the minimum requirements for the software so that's probably the underlying cause. The exported video is completely fine, thank you for suggesting that!