diff --git a/mozilla/testing/performance/talos/cmanager_mac.py b/mozilla/testing/performance/talos/cmanager_mac.py
index 98eaa981e64..10e1dbdcd7f 100644
--- a/mozilla/testing/performance/talos/cmanager_mac.py
+++ b/mozilla/testing/performance/talos/cmanager_mac.py
@@ -60,32 +60,32 @@ import ffprocess
 
 def GetProcessData(pid):
   """Runs a ps on the process identified by pid and returns the output line
-    as a list (uid, pid, ppid, cpu, pri, ni, vsz, rss, wchan, stat, tt, time, command)
+    as a list (pid, vsz, rss)
   """
-  command = ['ps -Acup'+str(pid)]
+  command = ['ps -o pid,vsize,rss -p'+str(pid)]
   handle = subprocess.Popen(command, stdout=subprocess.PIPE, universal_newlines=True, shell=True)
   handle.wait()
   data = handle.stdout.readlines()
   
-  # find all matching processes and add them to the list
-  for line in data:
-    if line.find(str(pid)) >= 0:
-      # splits by whitespace
-      line = line.split()
-      if (line[1] == str(pid)):
-        return line
+  # First line is header output should look like:
+  # PID      VSZ    RSS
+  # 3210    75964    920 
+  line = data[1]
+  line = line.split()
+  if (line[0] == str(pid)):
+      return line
 
 def GetPrivateBytes(pid):
   """Calculate the amount of private, writeable memory allocated to a process.
   """
   psData = GetProcessData(pid)
-  return psData[5]
+  return psData[2]
 
 
 def GetResidentSize(pid):
   """Retrieve the current resident memory for a given process"""
   psData = GetProcessData(pid)
-  return psData[4]
+  return psData[1]
 
 def GetCpuTime(pid):
   # return all zeros for now on this platform as per 7/18/07 perf meeting