That's only ~1.5M DOF - not really that many.
Pics? Upload model? Solver? What are you trying to accomplish? Have you tried refining the mesh?
Initial run was with using curved draft mesh, this solved ok up to 10% then message came up
force step is less than 0.01% of load, then stopped! with Large displacement iterations reaching 181, after 5 days, frustrating
Reduced elements from 1,5 million to 460,000 to get it to solve using standard mesh
Its a thin stack of multiple layers shaped like an glass lens frame with a flexible inner membrane, includes thermal shrink and forced deformation.
Iterative solver with Large Displacement Fails to solve
Sparse Solve with Large Displacement working, but very slow
Found Rouge contacts, these may have been the cause
Refined mesh further, as contacts may have been missing each other, on contacting added assume gap is closed
Re-running Analysis, Iterative Solver with Large Displacement
Lets see how it goes
Usually I find that Large Displacement warning only comes up if I have contact errors or gaps which I didn't spot.
One trick is to use "Use soft springs to stabilise model" which stops the model from displacing too much. This is usually enough for the solver to finish, and then you can see which parts have moved in an unexpected way and fix the contacts/geometry errors.
The FFE solver is usually quickest but doesn't work with large displacement. Uncheck lager displacement, check use soft springs, use FFE solver, and try again.
Hope that helps