Joe Rossignol / MacRumors:

Apple adds a 512GB RAM configuration for the Mac Studio with the M5 Ultra chip, starting at $22,299; the M5 Max model maxes out at 128GB of RAM  —  Starting today, the Mac Studio with the M5 Ultra chip can be configured with 512GB of RAM, with U.S. pricing starting at $22,299.

Joe Rossignol / MacRumors:

Apple adds a 512GB RAM configuration for the Mac Studio with the M5 Ultra chip, starting at $22,299; the M5 Max model maxes out at 128GB of RAM  —  Starting today, the Mac Studio with the M5 Ultra chip can be configured with 512GB of RAM, with U.S. pricing starting at $22,299.

Source: TechMeme
Source Link: https://www.techmeme.com/261028/p45#a261028p45