diff --git a/SocketStudy/PComm/PClient.cs b/SocketStudy/PComm/PClient.cs
index 7ab6bf8..9a871d5 100644
--- a/SocketStudy/PComm/PClient.cs
+++ b/SocketStudy/PComm/PClient.cs
@@ -15,7 +15,8 @@ namespace PComm
 {
 	public class PClient
 	{
-		private readonly int BUFF_SIZE = 1024 * 50;
+		private readonly int BUFF_SIZE = 1000 * 50; // 50kB
+		private readonly int LARGE_DATA_SIZE_THRESHOLD = 1000000; // 1MB
 
 		public delegate void ClientReceivedHandler(PClient sender, PDataType dataType, byte[] data);
 		public event ClientReceivedHandler OnReceived;
@@ -158,8 +159,9 @@ namespace PComm
 				socket.Receive(sizeBuff, sizeBuff.Length, SocketFlags.None);
 				int dataSize = BitConverter.ToInt32(sizeBuff, 0);
 
-				// ready to receive data;
-				Thread.Sleep(100);
+				// if data size is large, ready to receive data;
+				if (dataSize >= LARGE_DATA_SIZE_THRESHOLD)
+					Thread.Sleep(100);
 
 				using (MemoryStream ms = new MemoryStream())
 				{