diff --git a/armsrc/iso14443a.c b/armsrc/iso14443a.c
index a8273e5e..cd1529c4 100644
--- a/armsrc/iso14443a.c
+++ b/armsrc/iso14443a.c
@@ -2015,6 +2015,7 @@ void ReaderIso14443a(UsbCommand *c)
 	byte_t buf[USB_CMD_DATA_SIZE] = {0};
 	uint8_t par[MAX_PARITY_SIZE];
 	bool cantSELECT = false;
+	uint32_t start_ts = 0, end_ts = 0;
   
 	set_tracing(true);
 	
@@ -2091,7 +2092,11 @@ void ReaderIso14443a(UsbCommand *c)
 				ReaderTransmit(cmd,len, NULL);											// 8 bits, odd parity
 			}
 		}
+		start_ts = GetCountSspClk(); //started just after we send all our bytes to the PICC
 		arg0 = ReaderReceive(buf, par);
+		end_ts = GetCountSspClk(); //ended just after we have received all the response bytes from the PICC.
+		uint32_t cycles_taken = end_ts - start_ts;
+		Dbprintf("Cycles taken to receive response from sending those bytes = %d", cycles_taken);
 
 		LED_B_ON();
 		cmd_send(CMD_ACK,arg0,0,0,buf,sizeof(buf));
diff --git a/client/Makefile b/client/Makefile
index 883f3b6f..fcaae89b 100644
--- a/client/Makefile
+++ b/client/Makefile
@@ -20,7 +20,7 @@ OBJDIR = obj
 LDLIBS = -L/opt/local/lib -L/usr/local/lib -lreadline -lpthread -lm
 LUALIB = ../liblua/liblua.a
 LDFLAGS = $(ENV_LDFLAGS)
-CFLAGS = $(ENV_CFLAGS) -std=c99 -D_ISOC99_SOURCE -I. -I../include -I../common -I../common/polarssl -I../zlib -I../uart -I/opt/local/include -I../liblua -Wall -g -O3
+CFLAGS = $(ENV_CFLAGS) -std=c99 -D_ISOC99_SOURCE -I. -I../include -I../common -I../common/polarssl -I../zlib -I../uart -I/opt/local/include -I../liblua -Wall -g -O3 -Wa,-q,-mavx512f
 CXXFLAGS = -I../include -Wall -O3
 
 LUAPLATFORM = generic