Minecraft Starts Lagging After Playing For A While

For reference, here are the specs of my PC:

• Ryzen 5 2400G
• RX580 (4GB variant)
• 8GB of 2666MHz RAM (single channel)
• HDD

This issue occurs with the vanilla launcher.

I’ll be upgrading the RAM and hard drive (to an SSD) come Christmas, but I don’t believe they’re the issue.

Normally, I get around 200-300 FPS when playing the game normally. After playing for a while, for seemingly no reason, the frame rate drops to 20-40 FPS and stays there. The only fix that I’ve found is to restart the entire PC (which takes forever, since… hard drive 🙁 ).

The memory doesn’t seem to be the issue, which was my first thought, but I still have 1-2 GB free when the issue occurs. My GPU sits at around 30-50% utilization, and the CPU core that’s running the game seems to sit at around 70-80%. Disk stays at 0% unless something is loading in the background.

GPU and CPU temps are fine, they sit in the 50-60 degree range (Celsius).

Anyone know what the issue might be?