64GB RAM won't fix stuttering in modded Minecraft.

No.

Stuttering in modded Minecraft with shaders isn’t a RAM problem past a point. 8GB of allocated RAM is usually enough for 200+ mods. Bumping to 16GB allocated is the sweet spot. Going to 64GB total system RAM does nothing if you already have 16GB allocated—Java doesn’t use the rest for Minecraft.

The real culprits are:

• Java garbage collection – Minecraft’s Java garbage collection pauses cause the classic hitch. This is a JVM tuning thing, not a RAM size thing.
• CPU single-thread performance – Minecraft runs mostly on one core. Shaders and complex mods hammer that core. More RAM won’t help if your CPU’s single-thread speed is middling.
• GPU for shaders – Shaders are GPU-heavy. If your GPU is the bottleneck, RAM won’t save you.
• Mod conflicts or bad code – Some mods are just poorly written. Allocating 64GB of RAM doesn’t fix bad code.

If you’re already at 16GB allocated and still stuttering, look at a faster CPU, better GPU, and use a JVM argument like -XX:+UseG1GC with appropriate tuning. Or try Sodium and Lithium (Fabric) instead of Optifine. Your wallet will thank you.

Don’t throw more RAM at a problem that isn’t about RAM.