In principle 64-bit LispWorks can grow to almost 16 TB but it is intentionally limited to a defined range in order to avoid clashes with other software as shown in Default range for 64-bit LispWorks heap.
Apple silicon (arm64) Macintosh
old x86_64 Linux
Effective limit around 160 GB.
modern x86_64 Linux
Normally 64-bit LispWorks for Linux automatically adjusts its default heap size on startup according to whether it runs on "old Linux" or "new Linux". On old systems, LispWorks sets the end of its range to
x7000000000. On new systems, it sets the end to
#x44000000000, thus giving a range of 4 TB. However, if the size is given explicitly by command line argument
--reserve-size or InitLispWorks in a dynamic library, then this overrides the automatic adjustment.
LispWorks® User Guide and Reference Manual - 01 Dec 2021 19:30:25