gc-cons-threshold

gc-cons-threshold is a variable defined in `C source code'.
Its value is

800000

Documentation:
Number of bytes of consing between garbage collections.
Garbage collection can happen automatically once this many bytes have been
allocated since the last garbage collection. All data types count.

Garbage collection happens automatically only when `eval' is called.

By binding this temporarily to a large number, you can effectively
prevent garbage collection during a part of the program.
See also `gc-cons-percentage'.

You can customize this variable.