diff --git a/src/mainboard/google/butterfly/devicetree.cb b/src/mainboard/google/butterfly/devicetree.cb
index ca8118abab..e7a50c0c57 100644
--- a/src/mainboard/google/butterfly/devicetree.cb
+++ b/src/mainboard/google/butterfly/devicetree.cb
@@ -58,7 +58,10 @@ chip northbridge/intel/sandybridge
 
 			register "ide_legacy_combined" = "0x0"
 			register "sata_ahci" = "0x1"
-			register "sata_port_map" = "0x3"	#enable SATA ports 0 & 1
+			# Enable SATA ports 0 & 1
+			register "sata_port_map" = "0x3"
+			# Set max SATA speed to 3.0 Gb/s
+			register "sata_interface_speed_support" = "0x2"
 
 			# Enable EC Port 0x68/0x6C
 			register "gen1_dec" = "0x00040069"
diff --git a/src/mainboard/google/stout/devicetree.cb b/src/mainboard/google/stout/devicetree.cb
index c58a8d69e9..6e02020890 100644
--- a/src/mainboard/google/stout/devicetree.cb
+++ b/src/mainboard/google/stout/devicetree.cb
@@ -60,6 +60,8 @@ chip northbridge/intel/sandybridge
 			register "ide_legacy_combined" = "0x0"
 			register "sata_ahci" = "0x1"
 			register "sata_port_map" = "0x3"
+			# Set max SATA speed to 3.0 Gb/s
+			register "sata_interface_speed_support" = "0x2"
 
 			# Enable EC Port 0x68/0x6C
 			register "gen1_dec" = "0x00040069"