diff --git a/Makefile b/Makefile
index d5ff166..78862e9 100644
--- a/Makefile
+++ b/Makefile
@@ -18,8 +18,10 @@ p-server: socket_wrapper.o p-server.c
 	$(CC) -o p-server p-server.c socket_wrapper.o $(CFLAGS)
 p-client: socket_wrapper.o p-client.c
 	$(CC) -o p-client p-client.c socket_wrapper.o $(CFLAGS)
-p-slowclient: socket_wrapper.o p-client.c
-	$(CC) -o p-slowclient p-client.c socket_wrapper.o $(CFLAGS) -D SLOW_CLIENT=10
+p-mulclient: socket_wrapper.o p-client.c
+	$(CC) -o p-slowclient p-client.c socket_wrapper.o $(CFLAGS) -D MUL_CLIENT=10
+slowclient: socket_wrapper.o client.c
+	$(CC) -o slowclient client.c socket_wrapper.o $(CFLAGS) -D SLOW_CLIENT=1000
 
 .PHONY: clean moveall
 clean:
diff --git a/README.md b/README.md
index f58544d..2267855 100644
--- a/README.md
+++ b/README.md
@@ -26,7 +26,8 @@ For server
 - DEFAULT_MAX_THREAD_NUMBER: 10
    
 For client
-- SLOW_CLIENT(second unit)
+- MUL_CLIENT(second unit)
+- SLOW_CLIENT(microsecond unit, (buf_size/SLOW_CLIENT) bytes/usec)
 - DEFAULT_PROGRESS_BAR_WIDTH: 30
    
 For both
diff --git a/client.c b/client.c
index 611a8cd..63e2ad6 100644
--- a/client.c
+++ b/client.c
@@ -27,8 +27,11 @@ static const int TIMEOUT = 5;
 #else
 static const int TIMEOUT = DEFAULT_TIMEOUT;
 #endif
-
+#ifndef DEFAULT_PROGRESS_BAR_WIDTH
 static const int PROGRESS_BAR_WIDTH = 30;
+#else
+static const int PROGRESS_BAR_WIDTH = DEFAULT_PROGRESS_BAR_WIDTH;
+#endif
 /*========
  *Operation
  *========*/
@@ -41,8 +44,8 @@ int sendReadOp(int sock,const char * filename){
         perror("readop send fail");
         return -1;
     }
-    #ifdef SLOW_CLIENT
-    sleep(SLOW_CLIENT);
+    #ifdef MUL_CLIENT
+    sleep(MUL_CLIENT);
     #endif
     if(send(sock,filename,op.file_url_size,0)<0){
         perror("readop filename send fail");
@@ -66,7 +69,7 @@ void DisplayProgressBar(size_t offset,size_t total,double cur_progress){
             buf[i] = '=';
         else if(i == cur_pos)
             buf[i] = '>';
-        else buf[i] = ' ';
+        else buf[i] = '.';
     }
     printf("\r[%s]: %.2f%% bytes: %ld/%ld bytes",buf,cur_progress,total,offset);
 }
@@ -82,7 +85,7 @@ int recvFile(int sock, const char * filename,size_t file_size){
     int fd;
     size_t count = 0;
     int i;
-    int cur_progress = 1;
+    double cur_progress = 1;
     int return_value = 0;
     int buf_sz = getBufferSizeFrom(sock);
     uint8_t * buf = malloc(buf_sz*sizeof(*buf));
@@ -117,6 +120,9 @@ int recvFile(int sock, const char * filename,size_t file_size){
             fflush(stdout);
         }
         count += readed;
+        #ifdef SLOW_CLIENT
+            usleep(SLOW_CLIENT);
+        #endif
     }
     DisplayProgressBar100Percent(file_size);
 END:
diff --git a/p-client.c b/p-client.c
index 2fc1a88..ee26707 100644
--- a/p-client.c
+++ b/p-client.c
@@ -45,8 +45,8 @@ int sendReadOp(int sock,const char * filename){
         perror("readop send fail");
         return -1;
     }
-    #ifdef SLOW_CLIENT
-    sleep(SLOW_CLIENT);
+    #ifdef MUL_CLIENT
+    sleep(MUL_CLIENT);
     #endif
     if(send(sock,filename,op.file_url_size,0)<0){
         perror("readop filename send fail");
@@ -121,6 +121,9 @@ int recvFile(int sock, const char * filename,size_t file_size){
             fflush(stdout);
         }
         count += readed;
+        #ifdef SLOW_CLIENT
+            usleep(SLOW_CLIENT);
+        #endif
     }
     DisplayProgressBar100Percent(file_size);
 END: