64GB is fine for most Maya animation.

Probably not. Unless you’re loading multiple extremely heavy scenes with high-res textures, simulations, and tons of geometry all at once. For typical 3D animation work in Maya—rigging, modeling, animation, even moderate rendering—64GB is plenty with that CPU/GPU combo.

The bottleneck in 3D animation is usually single-core CPU speed (yours is great), GPU for viewport performance (4090 is overkill), and disk I/O. RAM only becomes a problem when you start paging to disk because you ran out. That happens when you have a scene with millions of polygons, multiple UDIM 8K textures, or a complex nCloth/simulation cache.

For most professional animation work—even on a heavy film or game asset—64GB is the sweet spot. 128GB is for people who regularly work with enormous point caches or need to keep multiple massive scenes open. If you’re not sure you need it, you probably don’t.

Future you can always upgrade, but don’t do it today.