diff --git a/config/zen/bli_cntx_init_zen.c b/config/zen/bli_cntx_init_zen.c
index be0eae8943..84f2eb279a 100644
--- a/config/zen/bli_cntx_init_zen.c
+++ b/config/zen/bli_cntx_init_zen.c
@@ -117,56 +117,34 @@ void bli_cntx_init_zen( cntx_t* cntx )
 	Multi Instance performance improvement of DGEMM when binded to a CCX
 	In Multi instance each thread runs a sequential DGEMM.
 
-	a) 	CPU freq 2.6 Ghz
+	a) 	If BLIS is run in a multi instance mode with 
+		CPU freq 2.6/2.2 Ghz
 		DDR4 clock frequency 2400Mhz
-		Multi instance mode
                 mc = 240, kc = 512, and nc = 2040
-	
-	b)	CPU freq 2.2Ghz
-		DDR4 clock frequency 2400Mhz
-		Multi Instance mode
-		either
-		mc = 240, kc = 512 and nc = 2040 
-			    (or)
-		mc = 390, kc = 512 and nc = 4080
+		has better performance on EPYC server, over the default block sizes.
 
-	c)  	If BLIS is run in Single Instance mode choose 
+	b)  	If BLIS is run in Single Instance mode 
 		mc = 510, kc = 1024 and nc = 4080
 
 */
 
 #ifdef BLIS_ENABLE_ZEN_BLOCK_SIZES
-	// Zen optmized level 3 cache block sizes
-	/************************************************************************
-		Below block sizes of DGEMM, works better in a multi instance mode,
-		for clock frequency of 2.2GHz and DDR4 clock frequency of 2400MHz
-	************************************************************************/
-	bli_blksz_init_easy( &blkszs[ BLIS_MC ],   144,  240,   144,    72 );
-	bli_blksz_init_easy( &blkszs[ BLIS_KC ],   256,  512,   256,   256 );
-	bli_blksz_init_easy( &blkszs[ BLIS_NC ],  4080,  2040,  4080,  4080 );
-
-    /***********************************************************************************
-        Below block sizes of DGEMM, gives better performance in a multi instance mode,
-        for clock frequency of 2.6GHz and DDR4 clock frequency of 2400MHz
-    **************************************************************************************/
-    //bli_blksz_init_easy( &blkszs[ BLIS_MC ],   144,  390,   144,    72 );
-    //bli_blksz_init_easy( &blkszs[ BLIS_KC ],   256,  512,   256,   256 );
-    //bli_blksz_init_easy( &blkszs[ BLIS_NC ],  4080,  4080,  4080,  4080 );
-
-    /******************************************************************************
-        BLIS on single instance mode, gives better perfomance with 
-        below mentioned default block size values
-    ********************************************************************************/
-    //bli_blksz_init_easy( &blkszs[ BLIS_MC ],   144,  510,   144,    72 );
-    //bli_blksz_init_easy( &blkszs[ BLIS_KC ],   256,  1024,   256,   256 );
-    //bli_blksz_init_easy( &blkszs[ BLIS_NC ],  4080,  4080,  4080,  4080 );
 
+        #if BLIS_ENABLE_SINGLE_INSTANCE_BLOCK_SIZES
+                bli_blksz_init_easy( &blkszs[ BLIS_MC ],   144,  510,   144,    72 );
+                bli_blksz_init_easy( &blkszs[ BLIS_KC ],   256,  1024,   256,   256 );
+                bli_blksz_init_easy( &blkszs[ BLIS_NC ],  4080,  4080,  4080,  4080 );
+        #else
+                bli_blksz_init_easy( &blkszs[ BLIS_MC ],   144,  240,   144,    72 );
+                bli_blksz_init_easy( &blkszs[ BLIS_KC ],   256,  512,   256,   256 );
+                bli_blksz_init_easy( &blkszs[ BLIS_NC ],  4080,  2040,  4080,  4080 );
+        #endif
 #else
-
-	bli_blksz_init_easy( &blkszs[ BLIS_MC ],   144,    72,   144,    72 );
-	bli_blksz_init_easy( &blkszs[ BLIS_KC ],   256,   256,   256,   256 );
-	bli_blksz_init_easy( &blkszs[ BLIS_NC ],  4080,   4080,  4080,  4080 );
+        bli_blksz_init_easy( &blkszs[ BLIS_MC ],   144,    72,   144,    72 );
+        bli_blksz_init_easy( &blkszs[ BLIS_KC ],   256,   256,   256,   256 );
+        bli_blksz_init_easy( &blkszs[ BLIS_NC ],  4080,   4080,  4080,  4080 );
 #endif
+
  	//bli_blksz_init_easy( &blkszs[ BLIS_NC ],  4080,  2040,  4080,  4080 );
 	bli_blksz_init_easy( &blkszs[ BLIS_AF ],     8,     8,    -1,    -1 );
 	bli_blksz_init_easy( &blkszs[ BLIS_DF ],     8,     8,    -1,    -1 );
diff --git a/config/zen/bli_family_zen.h b/config/zen/bli_family_zen.h
index 743c38f32a..281bebf507 100644
--- a/config/zen/bli_family_zen.h
+++ b/config/zen/bli_family_zen.h
@@ -46,6 +46,7 @@
 #define BLIS_ENABLE_SMALL_MATRIX
 #define BLIS_ENABLE_SMALL_MATRIX_TRSM
 
+
 // This will select the threshold below which small matrix code will be called.
 #define BLIS_SMALL_MATRIX_THRES        700
 #define BLIS_SMALL_M_RECT_MATRIX_THRES 160
@@ -56,5 +57,7 @@
 #define BLIS_SMALL_MATRIX_A_THRES_M_SYRK	96
 #define BLIS_SMALL_MATRIX_A_THRES_N_SYRK	128
 
+//This macro will enable  BLIS DGEMM to choose block sizes for a  single instance mode
+#define BLIS_ENABLE_SINGLE_INSTANCE_BLOCK_SIZES 	0
 //#endif