diff --git a/kernel/x86_64/dsymv_U.c b/kernel/x86_64/dsymv_U.c
index 1f22abe8d..267755c2f 100644
--- a/kernel/x86_64/dsymv_U.c
+++ b/kernel/x86_64/dsymv_U.c
@@ -28,43 +28,97 @@ USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 #include "common.h"
 
+
 #if defined(BULLDOZER)
 #include "dsymv_U_microk_bulldozer-2.c"
+#elif defined(NEHALEM)
+#include "dsymv_U_microk_nehalem-2.c"
 #endif
 
+#ifndef HAVE_KERNEL_4x4
+
+static void dsymv_kernel_4x4(BLASLONG n, FLOAT *a0, FLOAT *a1, FLOAT *a2, FLOAT *a3, FLOAT *xp, FLOAT *yp, FLOAT *temp1, FLOAT *temp2)
+{
+	FLOAT at0,at1,at2,at3;
+	FLOAT x;
+	FLOAT tmp2[4] = { 0.0, 0.0, 0.0, 0.0 };
+	FLOAT tp0;
+	FLOAT tp1;
+	FLOAT tp2;
+	FLOAT tp3;
+	BLASLONG i;
 
-#ifndef HAVE_KERNEL_8x2
+	tp0 = temp1[0];
+	tp1 = temp1[1];
+	tp2 = temp1[2];
+	tp3 = temp1[3];
+	
+	for (i=0; i<n; i++)
+	{
+		at0     = a0[i];
+		at1     = a1[i];
+		at2     = a2[i];
+		at3     = a3[i];
+		x       = xp[i];
+		yp[i]   += tp0 * at0 + tp1 *at1 + tp2 * at2 + tp3 * at3;
+		tmp2[0] += at0 * x;
+		tmp2[1] += at1 * x;
+		tmp2[2] += at2 * x;
+		tmp2[3] += at3 * x;
+
+	}
 
-static void dsymv_kernel_8x2(BLASLONG n, FLOAT *a0, FLOAT *a1, FLOAT *xp, FLOAT *yp, FLOAT *temp1, FLOAT *temp2)
+	temp2[0] += tmp2[0];
+	temp2[1] += tmp2[1];
+	temp2[2] += tmp2[2];
+	temp2[3] += tmp2[3];
+}
+
+#endif
+
+
+#ifndef HAVE_KERNEL_1x4
+
+static void dsymv_kernel_1x4(BLASLONG from, BLASLONG to, FLOAT *a0, FLOAT *a1, FLOAT *a2, FLOAT *a3, FLOAT *xp, FLOAT *yp, FLOAT *temp1, FLOAT *temp2)
 {
 	FLOAT at0,at1,at2,at3;
-	FLOAT tmp2[2] = { 0.0, 0.0 };
+	FLOAT x;
+	FLOAT tmp2[4] = { 0.0, 0.0, 0.0, 0.0 };
 	FLOAT tp0;
 	FLOAT tp1;
+	FLOAT tp2;
+	FLOAT tp3;
 	BLASLONG i;
 
 	tp0 = temp1[0];
 	tp1 = temp1[1];
+	tp2 = temp1[2];
+	tp3 = temp1[3];
 	
-	for (i=0; i<n; i+=2)
+	for (i=from; i<to; i++)
 	{
 		at0     = a0[i];
 		at1     = a1[i];
-		at2     = a0[i+1];
-		at3     = a1[i+1];
-		yp[i]   += tp0 * at0 + tp1 *at1;
-		yp[i+1] += tp0 * at2 + tp1 *at3;
-		tmp2[0] += at0 * xp[i] + at2 * xp[i+1];
-		tmp2[1] += at1 * xp[i] + at3 * xp[i+1];
+		at2     = a2[i];
+		at3     = a3[i];
+		x       = xp[i];
+		yp[i]   += tp0 * at0 + tp1 *at1 + tp2 * at2 + tp3 * at3;
+		tmp2[0] += at0 * x;
+		tmp2[1] += at1 * x;
+		tmp2[2] += at2 * x;
+		tmp2[3] += at3 * x;
 
 	}
-	temp2[0] = tmp2[0];
-	temp2[1] = tmp2[1];
 
+	temp2[0] += tmp2[0];
+	temp2[1] += tmp2[1];
+	temp2[2] += tmp2[2];
+	temp2[3] += tmp2[3];
 }
 
 #endif
 
+
 static void dsymv_kernel_8x1(BLASLONG n, FLOAT *a0, FLOAT *xp, FLOAT *yp, FLOAT *temp1, FLOAT *temp2)
 {
 	FLOAT at0,at1,at2,at3;
@@ -99,13 +153,16 @@ int CNAME(BLASLONG m, BLASLONG offset, FLOAT alpha, FLOAT *a, BLASLONG lda, FLOA
 	BLASLONG ix,iy;
 	BLASLONG jx,jy;
 	BLASLONG j;
+	BLASLONG j1;
+	BLASLONG j2;
 	BLASLONG m2;
 	FLOAT temp1;
 	FLOAT temp2;
 	FLOAT *xp, *yp;
-	FLOAT *a0,*a1;
-	FLOAT tmp1[2];
-	FLOAT tmp2[2];
+	FLOAT *a0,*a1,*a2,*a3;
+	FLOAT at0,at1,at2,at3;
+	FLOAT tmp1[4];
+	FLOAT tmp2[4];
 
 #if 0
 	if( m != offset )
@@ -145,37 +202,45 @@ int CNAME(BLASLONG m, BLASLONG offset, FLOAT alpha, FLOAT *a, BLASLONG lda, FLOA
 	xp = x;
 	yp = y;
 
-	m2 = m - ( mrange % 2 );
+	m2 = m - ( mrange % 4 );
 
-	for (j=m1; j<m2; j+=2)
+	for (j=m1; j<m2; j+=4)
 	{
 		tmp1[0] = alpha * xp[j];
 		tmp1[1] = alpha * xp[j+1];
+		tmp1[2] = alpha * xp[j+2];
+		tmp1[3] = alpha * xp[j+3];
 		tmp2[0] = 0.0;
 		tmp2[1] = 0.0;
+		tmp2[2] = 0.0;
+		tmp2[3] = 0.0;
 		a0    = &a[j*lda];
 		a1    = a0+lda;
-		FLOAT at0,at1;
-		BLASLONG j1 = (j/8)*8;		
+		a2    = a1+lda;
+		a3    = a2+lda;
+		j1 = (j/8)*8;		
 		if ( j1 )
-			dsymv_kernel_8x2(j1, a0, a1, xp, yp, tmp1, tmp2);
+			dsymv_kernel_4x4(j1, a0, a1, a2, a3, xp, yp, tmp1, tmp2);
+		if ( j1 < j )
+			dsymv_kernel_1x4(j1, j,  a0, a1, a2, a3, xp, yp, tmp1, tmp2);
 
-		for (i=j1; i<j; i++)
+		j2 = 0;
+		for ( j1 = j ; j1 < j+4 ; j1++ )
 		{
-			at0     = a0[i];
-			at1     = a1[i];
-			yp[i]   += tmp1[0] * at0 + tmp1[1] *at1;
-			tmp2[0] += at0 * xp[i];
-			tmp2[1] += at1 * xp[i];
-			
-		}
+			temp1 = tmp1[j2];
+			temp2 = tmp2[j2];
+			a0    = &a[j1*lda];
+			for ( i=j ; i<j1; i++ )
+			{
+				yp[i] += temp1 * a0[i];	
+				temp2 += a0[i] * xp[i];
+				
+			}
+			y[j1] += temp1 * a0[j1] + alpha * temp2;
+			j2++;
 
-		at1     = a1[j];
-		yp[j]   += tmp1[1] * at1;
-		tmp2[1] += at1 * xp[j];
+		}
 
-		yp[j]   += tmp1[0] * a0[j]   + alpha * tmp2[0];
-		yp[j+1] += tmp1[1] * a1[j+1] + alpha * tmp2[1];
 	}
 
 	for ( ; j<m; j++)
@@ -184,7 +249,7 @@ int CNAME(BLASLONG m, BLASLONG offset, FLOAT alpha, FLOAT *a, BLASLONG lda, FLOA
 		temp2 = 0.0;
 		a0    = &a[j*lda];
 		FLOAT at0;
-		BLASLONG j1 = (j/8)*8;		
+		j1 = (j/8)*8;		
 
 		if ( j1 )
 			dsymv_kernel_8x1(j1, a0, xp, yp, &temp1, &temp2);
diff --git a/kernel/x86_64/dsymv_U_microk_bulldozer-2.c b/kernel/x86_64/dsymv_U_microk_bulldozer-2.c
index 3b035222b..492920253 100644
--- a/kernel/x86_64/dsymv_U_microk_bulldozer-2.c
+++ b/kernel/x86_64/dsymv_U_microk_bulldozer-2.c
@@ -25,10 +25,10 @@ OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
 USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *****************************************************************************/
 
-#define HAVE_KERNEL_8x2 1
-static void dsymv_kernel_8x2( BLASLONG n, FLOAT *a1, FLOAT *a2, FLOAT *x, FLOAT *y, FLOAT *temp1, FLOAT *temp2) __attribute__ ((noinline));
+#define HAVE_KERNEL_4x4 1
+static void dsymv_kernel_4x4( BLASLONG n, FLOAT *a0, FLOAT *a1, FLOAT *a2, FLOAT *a3, FLOAT *x, FLOAT *y, FLOAT *temp1, FLOAT *temp2) __attribute__ ((noinline));
 
-static void dsymv_kernel_8x2(BLASLONG n, FLOAT *a0, FLOAT *a1, FLOAT *x, FLOAT *y, FLOAT *temp1, FLOAT *temp2)
+static void dsymv_kernel_4x4(BLASLONG n, FLOAT *a0, FLOAT *a1, FLOAT *a2, FLOAT *a3, FLOAT *x, FLOAT *y, FLOAT *temp1, FLOAT *temp2)
 {
 
 	BLASLONG register i = 0;
@@ -37,62 +37,73 @@ static void dsymv_kernel_8x2(BLASLONG n, FLOAT *a0, FLOAT *a1, FLOAT *x, FLOAT *
 	(
 	"vxorpd		%%xmm0 , %%xmm0 , %%xmm0     \n\t"	// temp2[0]
 	"vxorpd		%%xmm1 , %%xmm1 , %%xmm1     \n\t"	// temp2[1]
-	"vmovddup	(%6),    %%xmm2	             \n\t"	// temp1[0]
-	"vmovddup      8(%6),    %%xmm3	             \n\t"	// temp1[1]
+	"vxorpd		%%xmm2 , %%xmm2 , %%xmm2     \n\t"	// temp2[2]
+	"vxorpd		%%xmm3 , %%xmm3 , %%xmm3     \n\t"	// temp2[3]
+	"vmovddup	(%8),    %%xmm4	             \n\t"	// temp1[0]
+	"vmovddup  8(%8),    %%xmm5	             \n\t"	// temp1[1]
+	"vmovddup 16(%8),    %%xmm6	             \n\t"	// temp1[1]
+	"vmovddup 24(%8),    %%xmm7	             \n\t"	// temp1[1]
 
 	"xorq		%0,%0			     \n\t"
 
-	".align 16				 \n\t"
-	".L01LOOP%=:				 \n\t"
-
-	"prefetcht0	 192(%4,%0,8)		       \n\t"
-	"vmovups	(%4,%0,8), %%xmm4	 \n\t"	// 2 * a0
-	"vmovups      16(%4,%0,8), %%xmm5	 \n\t"	// 2 * a0
-	"prefetcht0	 192(%2,%0,8)		       \n\t"
-	"vmovups	(%2,%0,8), %%xmm8	 \n\t"	// 2 * x
-	"vmovups      16(%2,%0,8), %%xmm9	 \n\t"	// 2 * x
-	"prefetcht0	 192(%3,%0,8)		       \n\t"
-	"vmovups      32(%4,%0,8), %%xmm6	 \n\t"	// 2 * a0
-	"vmovups      48(%4,%0,8), %%xmm7	 \n\t"	// 2 * a0
-	"vmovups      32(%2,%0,8), %%xmm10	 \n\t"	// 2 * x
-	"vmovups      48(%2,%0,8), %%xmm11	 \n\t"	// 2 * x
-
-	"prefetcht0	 192(%5,%0,8)		            \n\t"
-	"vfmaddpd    (%3,%0,8), %%xmm2 , %%xmm4 , %%xmm12   \n\t" // y += temp1 * a0
-	"vfmaddpd      %%xmm0 , %%xmm8 , %%xmm4 , %%xmm0    \n\t" // temp2 += a0 * x
-	"vfmaddpd  16(%3,%0,8), %%xmm2 , %%xmm5 , %%xmm13   \n\t" // y += temp1 * a0
-	"vmovups	(%5,%0,8), %%xmm4	            \n\t"	// 2 * a1
-	"vfmaddpd      %%xmm0 , %%xmm9 , %%xmm5 , %%xmm0    \n\t" // temp2 += a0 * x
-	"vfmaddpd  32(%3,%0,8), %%xmm2 , %%xmm6 , %%xmm14   \n\t" // y += temp1 * a0
-	"vmovups      16(%5,%0,8), %%xmm5	            \n\t"	// 2 * a1
-	"vfmaddpd      %%xmm0 , %%xmm10, %%xmm6 , %%xmm0    \n\t" // temp2 += a0 * x
-	"vfmaddpd  48(%3,%0,8), %%xmm2 , %%xmm7 , %%xmm15   \n\t" // y += temp1 * a0
-	"vmovups      32(%5,%0,8), %%xmm6	            \n\t"	// 2 * a1
-	"vfmaddpd      %%xmm0 , %%xmm11, %%xmm7 , %%xmm0    \n\t" // temp2 += a0 * x
-	"vmovups      48(%5,%0,8), %%xmm7	            \n\t"	// 2 * a1
-
-	"vfmaddpd %%xmm12, %%xmm3 , %%xmm4 , %%xmm12   \n\t" // y += temp1 * a1
-	"vfmaddpd %%xmm13, %%xmm3 , %%xmm5 , %%xmm13   \n\t" // y += temp1 * a1
-	"vmovups  %%xmm12,   (%3,%0,8)		       \n\t"	// 2 * y
-	"vfmaddpd %%xmm14, %%xmm3 , %%xmm6 , %%xmm14   \n\t" // y += temp1 * a1
-	"vmovups  %%xmm13, 16(%3,%0,8)		       \n\t"	// 2 * y
-	"vfmaddpd %%xmm15, %%xmm3 , %%xmm7 , %%xmm15   \n\t" // y += temp1 * a1
-	"vmovups  %%xmm14, 32(%3,%0,8)		       \n\t"	// 2 * y
-
-	"vfmaddpd %%xmm1 , %%xmm8 , %%xmm4 , %%xmm1   \n\t" // temp2 += a1 * x
-	"vfmaddpd %%xmm1 , %%xmm9 , %%xmm5 , %%xmm1   \n\t" // temp2 += a1 * x
-	"vmovups  %%xmm15, 48(%3,%0,8)		      \n\t"	// 2 * y
-	"vfmaddpd %%xmm1 , %%xmm10, %%xmm6 , %%xmm1   \n\t" // temp2 += a1 * x
-	"vfmaddpd %%xmm1 , %%xmm11, %%xmm7 , %%xmm1   \n\t" // temp2 += a1 * x
-
-        "addq		$8, %0	  	 	      \n\t"
-	"subq	        $8, %1			      \n\t"		
+	".align 16				     \n\t"
+	".L01LOOP%=:				     \n\t"
+
+	"vmovups	(%4,%0,8), %%xmm12	           \n\t"  // 2 * a
+	"vmovups	(%2,%0,8), %%xmm8	           \n\t"  // 2 * x
+	"vmovups	(%3,%0,8), %%xmm9	           \n\t"  // 2 * y
+
+	"vmovups	(%5,%0,8), %%xmm13	           \n\t"  // 2 * a
+
+	"vfmaddpd	%%xmm0 , %%xmm8, %%xmm12 , %%xmm0  \n\t"  // temp2 += x * a
+	"vfmaddpd	%%xmm9 , %%xmm4, %%xmm12 , %%xmm9  \n\t"  // y     += temp1 * a
+	"vmovups	(%6,%0,8), %%xmm14	           \n\t"  // 2 * a
+
+	"vfmaddpd	%%xmm1 , %%xmm8, %%xmm13 , %%xmm1  \n\t"  // temp2 += x * a
+	"vfmaddpd	%%xmm9 , %%xmm5, %%xmm13 , %%xmm9  \n\t"  // y     += temp1 * a
+	"vmovups	(%7,%0,8), %%xmm15	           \n\t"  // 2 * a
+
+	"vmovups	16(%3,%0,8), %%xmm11	           \n\t"  // 2 * y
+	"vfmaddpd	%%xmm2 , %%xmm8, %%xmm14 , %%xmm2  \n\t"  // temp2 += x * a
+	"vmovups	16(%4,%0,8), %%xmm12	           \n\t"  // 2 * a
+	"vfmaddpd	%%xmm9 , %%xmm6, %%xmm14 , %%xmm9  \n\t"  // y     += temp1 * a
+	"vmovups	16(%2,%0,8), %%xmm10	           \n\t"  // 2 * x
+
+	"vfmaddpd	%%xmm3 , %%xmm8, %%xmm15 , %%xmm3  \n\t"  // temp2 += x * a
+	"vfmaddpd	%%xmm9 , %%xmm7, %%xmm15 , %%xmm9  \n\t"  // y     += temp1 * a
+
+	"vmovups	16(%5,%0,8), %%xmm13	           \n\t"  // 2 * a
+	"vmovups	16(%6,%0,8), %%xmm14	           \n\t"  // 2 * a
+
+	"vfmaddpd	%%xmm0 , %%xmm10, %%xmm12 , %%xmm0  \n\t"  // temp2 += x * a
+	"vfmaddpd	%%xmm11 , %%xmm4, %%xmm12 , %%xmm11  \n\t"  // y     += temp1 * a
+
+	"vmovups	16(%7,%0,8), %%xmm15	           \n\t"  // 2 * a
+	"vfmaddpd	%%xmm1 , %%xmm10, %%xmm13 , %%xmm1  \n\t"  // temp2 += x * a
+	"vfmaddpd	%%xmm11 , %%xmm5, %%xmm13 , %%xmm11  \n\t"  // y     += temp1 * a
+
+	"vfmaddpd	%%xmm2 , %%xmm10, %%xmm14 , %%xmm2  \n\t"  // temp2 += x * a
+	"addq		$4 , %0	  	 	      \n\t"
+	"vfmaddpd	%%xmm11 , %%xmm6, %%xmm14 , %%xmm11  \n\t"  // y     += temp1 * a
+
+	"vfmaddpd	%%xmm3 , %%xmm10, %%xmm15 , %%xmm3  \n\t"  // temp2 += x * a
+	"vfmaddpd	%%xmm11 , %%xmm7, %%xmm15 , %%xmm11  \n\t"  // y     += temp1 * a
+	"subq	        $4 , %1			      \n\t"		
+
+	"vmovups	%%xmm9 ,  -32(%3,%0,8)		   \n\t"
+	"vmovups	%%xmm11 , -16(%3,%0,8)		   \n\t"
+
 	"jnz		.L01LOOP%=		      \n\t"
 
 	"vhaddpd        %%xmm0, %%xmm0, %%xmm0  \n\t"
 	"vhaddpd        %%xmm1, %%xmm1, %%xmm1  \n\t"
-	"vmovsd         %%xmm0 , (%7)		\n\t"	// save temp2
-	"vmovsd         %%xmm1 ,8(%7)		\n\t"	// save temp2
+	"vhaddpd        %%xmm2, %%xmm2, %%xmm2  \n\t"
+	"vhaddpd        %%xmm3, %%xmm3, %%xmm3  \n\t"
+
+	"vmovsd         %%xmm0 ,  (%9)		\n\t"	// save temp2
+	"vmovsd         %%xmm1 , 8(%9)		\n\t"	// save temp2
+	"vmovsd         %%xmm2 ,16(%9)		\n\t"	// save temp2
+	"vmovsd         %%xmm3 ,24(%9)		\n\t"	// save temp2
 
 	:
         : 
@@ -100,10 +111,12 @@ static void dsymv_kernel_8x2(BLASLONG n, FLOAT *a0, FLOAT *a1, FLOAT *x, FLOAT *
 	  "r" (n),  	// 1
           "r" (x),      // 2
           "r" (y),      // 3
-          "r" (a0),  // 4
-          "r" (a1),  // 5
-          "r" (temp1),  // 6
-          "r" (temp2)   // 7
+          "r" (a0),     // 4
+          "r" (a1),     // 5
+          "r" (a2),     // 6
+          "r" (a3),     // 7
+          "r" (temp1),  // 8
+          "r" (temp2)   // 9
 	: "cc", 
 	  "%xmm0", "%xmm1", "%xmm2", "%xmm3", 
 	  "%xmm4", "%xmm5", "%xmm6", "%xmm7",