--- make.conf	2006-03-19 18:40:11.000000000 +0100
+++ make.conf.ppc64	2006-03-19 18:26:21.000000000 +0100
@@ -23,6 +23,13 @@
 # Example:
 #USE="X gtk gnome -alsa"
 
+# Host Setting
+# ============
+#
+# All PowerPC64 systems should use this host setting:
+
+CHOST="powerpc64-unknown-linux-gnu"
+
 # Host and optimization settings 
 # ==============================
 #
@@ -33,9 +40,38 @@
 # package (and in some cases the libraries it uses) at default optimizations
 # before reporting errors to developers.
 #
-# Please refer to the GCC manual for a list of possible values.
+# -mtune=<cpu-type> for PowerPC64 systems instructs the gcc compiler that
+# it can use instruction scheduling specific for that type of processor
+# specified
+#
+# -mcpu=<cpu-type> for PowerPC64 systems selects the type of processor you want
+# to optimize your code for.   Code generated under those options will run best
+# on that processor.
+#
+# -mcpu=<cpu-type>  and -mtune=<cpu-type>  should both be specified
+#
+# GCC 3.x supports many ppc64 processor types including: power3, power4,
+# 970 (aka G5), and power5.
+#
+# RS64 processors should specify power3. 
+#
+# Additional options of interest:
+#
+# -maltivec enables optional altivec support and should be used
+# only for 970 processors.  It also requires that you have
+# the alitvec option compiled into your kernel to take full advantage of this
+# feature.  Note: you should also include -mabi=altivec flag if using this option.
 #
-#CFLAGS="-O2 -pipe"
+# -O3 for the most part seems ok but should be used with caution as
+# for instance app-editors/vim has problems if it is used. -O2 is a
+# good selection.
+#
+#Example CFLAGS setting
+#CFLAGS="-O2 -pipe -mcpu=970 -mtune=970 -maltivec -mabi=altivec"
+#
+#or
+#
+#CFLAGS="-O2 -pipe -mcpu=power3 -mtune=power3"
 #
 # If you set a CFLAGS above, then this line will set your default C++ flags to
 # the same settings.
@@ -61,7 +97,10 @@
 # DO NOT PUT ANYTHING BUT YOUR SPECIFIC ~ARCHITECTURE IN THE LIST.
 # IF YOU ARE UNSURE OF YOUR ARCH, OR THE IMPLICATIONS, DO NOT MODIFY THIS.
 #
-#ACCEPT_KEYWORDS="~arch"
+# Note: this really shouldn't be enabled until _AFTER_ you bootstrap and emerge
+# system.  If you want the testing things update after these steps are completed.
+#
+#ACCEPT_KEYWORDS="ppc64"
 
 # Portage Directories
 # ===================