diff --git a/src/service/backends/cpu.py b/src/service/backends/cpu.py
index dbdc1f1..ee58c97 100755
--- a/src/service/backends/cpu.py
+++ b/src/service/backends/cpu.py
@@ -1,13 +1,38 @@
 import os
 from common import *
 def list_cpu():
-    i = 0
     ret = []
+    for i in range(0, get_num_of_cpu()):
+        ret.append("cpu"+str(i))
+    return ret
+
+def get_num_of_cpu():
+    i = 0
     while os.path.exists("/sys/devices/system/cpu/cpu"+str(i)):
         i += 1
-        ret.append("cpu"+str(i))
+    return i
+
+def list_little_cpu():
+    max_all = 0
+    ret = []
+    for i in range(0, get_num_of_cpu()):
+        with open("/sys/devices/system/cpu/cpu{}//cpufreq/scaling_max_freq".format(i), "r") as f:
+            freq = int(f.read())
+            if freq > max_all:
+                max_all = freq
+    for i in range(0, get_num_of_cpu()):
+        with open("/sys/devices/system/cpu/cpu{}//cpufreq/scaling_max_freq".format(i), "r") as f:
+            freq = int(f.read())
+            if freq < max_all:
+                ret.append("cpu"+str(i))
     return ret
 
+def list_big_cpu():
+    all_cpu = list_cpu()
+    for cpu in list_little_cpu():
+        all_cpu.remove(cpu)
+    return all_cpu
+
 def change_cpu_status(core, status):
     log("New core status: {} = {}".format(core, status))
     if not os.path.exists("/sys/devices/system/cpu/cpu"+str(core)+"/online"):
diff --git a/src/service/backends/power.py b/src/service/backends/power.py
index 1ca0ff5..d6a088f 100755
--- a/src/service/backends/power.py
+++ b/src/service/backends/power.py
@@ -60,14 +60,16 @@ def _powersave():
 
     if get("core",True,"power"):
         # disable cpu core
-        cpus = list_cpu()
-        dnum = len(cpus) * float(get("core-ratio",0.5,"powersave"))
-        if len(cpus) <= 4:
-            dnum = 0
-        elif len(cpus) - dnum < 4:
-            dnum = 4
-        for cpu in range(len(cpus) - int(dnum), len(cpus)):
-            change_cpu_status(cpu,False)
+        def cpu_disable_event(cpus, min):
+            dnum = len(cpus) * float(get("core-ratio",0.5,"powersave"))
+            if len(cpus) <= min:
+                dnum = 0
+            elif len(cpus) - dnum < min:
+                dnum = min
+            for cpu in range(len(cpus) - int(dnum), len(cpus)):
+                change_cpu_status(cpu,False)
+        cpu_disable_event(list_big_cpu(), 4)
+        cpu_disable_event(list_little_cpu(), 0)
 
     if not is_acpi_supported():
         return