Supposedly 128 GB although I doubt vendors will ship that much.

the snapdragon x2 elite extreme (X2E-96-100) SoC supports "128GB+" but qualcomm hasn't specified what the max limit is. this soc also has higher memory bandwidth (228GB/s over 192-bit bus) than the x2 elite.

also see https://wccftech.com/snapdragon-x2-elite-extreme-die-package...