diff --git a/src/arch/x86/car.ld b/src/arch/x86/car.ld
index 9d54037b7a..bbfd682934 100644
--- a/src/arch/x86/car.ld
+++ b/src/arch/x86/car.ld
@@ -122,6 +122,7 @@ _car_region_end = . + CONFIG_DCACHE_RAM_SIZE - (. - _car_region_start)
 }
 
 #if ENV_BOOTBLOCK
+. = ALIGN(64);
 _car_mtrr_end = .;
 _car_mtrr_start = _car_region_start;
 
diff --git a/src/cpu/intel/car/non-evict/cache_as_ram.S b/src/cpu/intel/car/non-evict/cache_as_ram.S
index 7186422595..91035dabb4 100644
--- a/src/cpu/intel/car/non-evict/cache_as_ram.S
+++ b/src/cpu/intel/car/non-evict/cache_as_ram.S
@@ -151,21 +151,16 @@ update_microcode:
 	jmp	update_bsp_microcode
 end_microcode_update:
 #endif
-	/* Disable caching to change MTRR's. */
+
+	/* Disable caching. */
 	movl	%cr0, %eax
 	orl	$CR0_CacheDisable, %eax
 	movl	%eax, %cr0
 
-	/* Clear the mask valid to disable the MTRR */
-	movl	$MTRR_PHYS_MASK(1), %ecx
-	rdmsr
-	andl	$(~MTRR_PHYS_MASK_VALID), %eax
-	wrmsr
-
-	/* Enable cache. */
-	movl	%cr0, %eax
-	andl	$(~(CR0_CacheDisable | CR0_NoWriteThrough)), %eax
 	invd
+
+	/* Enable caching */
+	andl	$(~(CR0_CacheDisable | CR0_NoWriteThrough)), %eax
 	movl	%eax, %cr0
 
 	/* enable the 'no eviction' mode */
@@ -175,36 +170,46 @@ end_microcode_update:
 	andl	$~2, %eax
 	wrmsr
 
-	/* Clear the cache memory region. This will also fill up the cache. */
-	cld
-	xorl	%eax, %eax
+	/* Fill up the cache next. */
 	movl	$_car_mtrr_start, %edi
-	movl	$_car_mtrr_size, %ecx
-	shr	$2, %ecx
-	rep	stosl
 
-	/* enable the 'no eviction run' state */
+	/* Number of loops. */
+	movl	$_car_mtrr_size, %ecx
+	shr	$6, %ecx
+	xorl	%ebx, %ebx
+	mov	$64, %bl
+
+1:
+	/*
+	 * BWG: *One* location in each 64-byte cache line must be written
+	 * to set all cached values to modified state.
+	 *
+	 * Value of %eax doesn't matter here. CAR is zeroed later.
+	 *
+	 * Zeroing the whole cache here *not* work when CR0.CD = 0.
+	 * Zeroing the whole cache here *does* work when CR0.CD = 1,
+	 * but will be a couple of times slower (4 times on Sandy Bridge).
+	 */
+	movl	%eax, (%edi)
+	addl	%ebx, %edi
+
+	loop	1b
+
+	/* enable the 'no eviction run' state. */
 	movl	$NoEvictMod_MSR, %ecx
 	rdmsr
-	orl	$3, %eax
-	wrmsr
-
-	post_code(POSTCODE_SOC_DISABLE_CACHE)
-	/* Enable Cache-as-RAM mode by disabling cache. */
-	movl	%cr0, %eax
-	orl	$CR0_CacheDisable, %eax
-	movl	%eax, %cr0
-
-	movl	$MTRR_PHYS_MASK(1), %ecx
-	rdmsr
-	orl	$MTRR_PHYS_MASK_VALID, %eax
+	or	$3, %al
 	wrmsr
 
 	post_code(POSTCODE_SOC_ENABLE_CACHE)
-	/* Enable cache. */
-	movl	%cr0, %eax
-	andl	$(~(CR0_CacheDisable | CR0_NoWriteThrough)), %eax
-	movl	%eax, %cr0
+
+	/* Now that CAR is enabled clear it. */
+	movl	$_car_mtrr_start, %edi
+	movl	$_car_mtrr_size, %ecx
+	cld
+	xorl	%eax, %eax
+	shr	$2, %ecx
+	rep	stosl
 
 	/* Setup the stack. */
 	mov	$_ecar_stack, %esp