diff --git a/README.md b/README.md
index 90e12aa..c481a68 100644
--- a/README.md
+++ b/README.md
@@ -66,7 +66,8 @@ ref: [GitFlow](http://nvie.com/posts/a-successful-git-branching-model/)
 - [ ] Embed the http proxy server [privoxy](http://www.privoxy.org/).
 
 ## Know Issue
-[Issue 1.]() Auto PAC & White list is not working on macOS 10.12 Serria because system proxy not allow [file:///](file:///) protocol.
+Solved [Issue 1.]() Auto PAC & White list is not working on macOS 10.12 Serria because system proxy not allow [file:///](file:///) protocol.
+[Issue 2.]() The net speed is how ever have some problem with macOS 10.12, welcome logs from all users.
 
 ## License
 
diff --git a/ShadowsocksX-NG/NetWorkMonitor.swift b/ShadowsocksX-NG/NetWorkMonitor.swift
index 1b41350..d56d74e 100755
--- a/ShadowsocksX-NG/NetWorkMonitor.swift
+++ b/ShadowsocksX-NG/NetWorkMonitor.swift
@@ -26,7 +26,24 @@ public class NetWorkMonitor: NSObject {
     
     func startUpdateTimer() {
         timer = NSTimer.scheduledTimerWithTimeInterval(1, target: self, selector: #selector(updateNetWorkData), userInfo: nil, repeats: true)
-        NSRunLoop.currentRunLoop().run()
+        if #available(OSX 10.12, *){
+            
+            let alertView = NSAlert()
+            alertView.messageText = "网速显示不支持 macOS 10.12 Sierra!"
+            alertView.informativeText = "因为 macOS 10.12 Sierra ABI 不稳定，因此暂时移除网速功能"
+            alertView.addButtonWithTitle("取消网速显示")
+            alertView.runModal()
+            let defaults = NSUserDefaults.standardUserDefaults()
+            defaults.setBool(false, forKey: "enable_showSpeed")
+            
+//            NSRunLoop.currentRunLoop().run()
+//            CFRunLoopRun()
+            
+        } else {
+            NSRunLoop.currentRunLoop().addTimer(timer!, forMode: NSRunLoopCommonModes)
+            NSRunLoop.currentRunLoop().run()
+            print(NSRunLoop.currentRunLoop().getCFRunLoop())
+        }
     }
 
     func stop(){
diff --git a/ShadowsocksX-NG/PingClient.swift b/ShadowsocksX-NG/PingClient.swift
index c3f4776..5318023 100644
--- a/ShadowsocksX-NG/PingClient.swift
+++ b/ShadowsocksX-NG/PingClient.swift
@@ -101,7 +101,7 @@ class PingServers:NSObject{
                     self.fastest = latency
                     self.fastest_id = i
                 }else{
-                    if latency < self.fastest{
+                    if Int(latency!) < Int(self.fastest!) {
                         self.fastest = latency
                         self.fastest_id = i
                     }