vector maximum length

Depends on the R platform, but much larger than that.  On most systems the 
maximum length will be 2^31-1 (over 2 billion), but on 32-bit systems the 
storage needed for the vector will hit its limit first.  You can expect to 
be able to use a small number of hundred million elements, depending on 
what they are, if you have enough RAM.

Hi, What is the maximum size of a vector in R?

I am trying to load in a vector with 1.6 million elements.

load as in load()?  In which case someone must have created it!

Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
1 South Parks Road,                     +44 1865 272866 (PA)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595