--- a/NEWS Wed Jan 02 16:32:53 2008 +0100
+++ b/NEWS Wed Jan 02 16:33:07 2008 +0100
@@ -72,6 +72,12 @@
*** System ***
+* Multithreading.max_threads := 0 refers to the number of actual CPU
+cores of the underlying machine, which is a good starting point for
+optimal performance tuning. The corresponding usedir option -M allows
+"max" as an alias for "0". WARNING: this does not work on certain
+versions of Mac OS (with Poly/ML 5.1).
+
* isatool tty runs Isabelle process with plain tty interaction;
optional line editor may be specified via ISABELLE_LINE_EDITOR
setting, the default settings attempt to locate "ledit" and "rlwrap".