diff --git a/perl-xCAT/xCAT/PPCpower.pm b/perl-xCAT/xCAT/PPCpower.pm
index 71dcd7233..c54127e48 100644
--- a/perl-xCAT/xCAT/PPCpower.pm
+++ b/perl-xCAT/xCAT/PPCpower.pm
@@ -192,6 +192,14 @@ sub powercmd_boot {
         my $state = power_status($data->{$id});
         my $op    = ($state =~ /^off$/) ? "on" : "reset";
 
+        # Attribute powerinterval in site table,
+        # to control the rpower forking speed
+        if ((defined($request->{op})) && ($request->{op} ne 'stat') && ($request->{op} ne 'status') 
+           && ($request->{op} ne 'state') && ($request->{op} ne 'off') && ($request->{op} ne 'softoff')) {
+            if(defined($request->{'powerinterval'}) && ($request->{'powerinterval'} ne '')) {
+                Time::HiRes::sleep($request->{'powerinterval'});
+            }    
+        } 
         ##############################
         # Send power command
         ##############################
@@ -279,6 +287,14 @@ sub powercmd {
     ####################################
 
     while (my ($name,$d) = each(%$hash) ) {
+        # Attribute powerinterval in site table,
+        # to control the rpower forking speed
+        if ((defined($request->{op})) && ($request->{op} ne 'stat') && ($request->{op} ne 'status') 
+           && ($request->{op} ne 'state') && ($request->{op} ne 'off') && ($request->{op} ne 'softoff')) {
+            if(defined($request->{'powerinterval'}) && ($request->{'powerinterval'} ne '')) {
+                Time::HiRes::sleep($request->{'powerinterval'});
+            }    
+        } 
         ################################
         # Send command to each LPAR
         ################################
diff --git a/perl-xCAT/xCAT/Schema.pm b/perl-xCAT/xCAT/Schema.pm
index 5154d6965..69596ebb9 100644
--- a/perl-xCAT/xCAT/Schema.pm
+++ b/perl-xCAT/xCAT/Schema.pm
@@ -656,6 +656,8 @@ site => {
    "              the node deployment, node discovery and power operations.\n\n".
    " ntpservers:  A comma delimited list of NTP servers for the cluster - often the\n".
    "              xCAT management node.\n\n".
+   " powerinterval:  The time of seconds that rpower command will wait between performing action on each target object,\n".
+   "                 it is useful especially for controlling the cluster boot up speed in large clusters.\n\n".
    " ppcmaxp:  The max # of processes for PPC hw ctrl.\n\n".
    " ppcretry:  The max # of PPC hw connection attempts before failing.\n\n".
    " ppctimeout:  The timeout, in milliseconds, to use when communicating with PPC hw.\n\n".