diff --git a/configs/README.txt b/configs/README.txt
index 096a6a54b80..2dba9d0f529 100644
--- a/configs/README.txt
+++ b/configs/README.txt
@@ -286,6 +286,8 @@ defconfig -- This is a configuration file similar to the Linux
 		  driver. Default is one.
 		CONFIG_MMCSD_READONLY -  Provide read-only access.  Default is
 		  Read/Write
+		CONFIG_MMCSD_SPICLOCK - Maximum SPI clock to drive MMC/SD card.
+		  Default is 20MHz.
 
 	TCP/IP and UDP support via uIP
 		CONFIG_NET - Enable or disable all network features
diff --git a/configs/eagle100/httpd/defconfig b/configs/eagle100/httpd/defconfig
index 044d5c5cb1b..e6b40982db0 100644
--- a/configs/eagle100/httpd/defconfig
+++ b/configs/eagle100/httpd/defconfig
@@ -350,8 +350,12 @@ CONFIG_FS_ROMFS=n
 #   Number of MMC/SD slots supported by the driver
 # CONFIG_MMCSD_READONLY
 #   Provide read-only access (default is read/write)
+# CONFIG_MMCSD_SPICLOCK - Maximum SPI clock to drive MMC/SD card.
+#   Default is 20MHz.
+#
 CONFIG_MMCSD_NSLOTS=1
 CONFIG_MMCSD_READONLY=n
+CONFIG_MMCSD_SPICLOCK=12500000
 
 #
 # TCP/IP and UDP support via uIP
diff --git a/configs/eagle100/nettest/defconfig b/configs/eagle100/nettest/defconfig
index c9679b551be..fd74f7bedb1 100644
--- a/configs/eagle100/nettest/defconfig
+++ b/configs/eagle100/nettest/defconfig
@@ -350,8 +350,12 @@ CONFIG_FS_ROMFS=n
 #   Number of MMC/SD slots supported by the driver
 # CONFIG_MMCSD_READONLY
 #   Provide read-only access (default is read/write)
+# CONFIG_MMCSD_SPICLOCK - Maximum SPI clock to drive MMC/SD card.
+#   Default is 20MHz.
+#
 CONFIG_MMCSD_NSLOTS=1
 CONFIG_MMCSD_READONLY=n
+CONFIG_MMCSD_SPICLOCK=12500000
 
 #
 # TCP/IP and UDP support via uIP
diff --git a/configs/eagle100/nsh/defconfig b/configs/eagle100/nsh/defconfig
index d40816e4227..4bcb2decff1 100644
--- a/configs/eagle100/nsh/defconfig
+++ b/configs/eagle100/nsh/defconfig
@@ -349,8 +349,12 @@ CONFIG_FS_ROMFS=n
 #   Number of MMC/SD slots supported by the driver
 # CONFIG_MMCSD_READONLY
 #   Provide read-only access (default is read/write)
+# CONFIG_MMCSD_SPICLOCK - Maximum SPI clock to drive MMC/SD card.
+#   Default is 20MHz.
+#
 CONFIG_MMCSD_NSLOTS=1
 CONFIG_MMCSD_READONLY=n
+CONFIG_MMCSD_SPICLOCK=12500000
 
 #
 # TCP/IP and UDP support via uIP
diff --git a/configs/eagle100/ostest/defconfig b/configs/eagle100/ostest/defconfig
index 41f811dd18e..cd430ca08dd 100644
--- a/configs/eagle100/ostest/defconfig
+++ b/configs/eagle100/ostest/defconfig
@@ -349,8 +349,12 @@ CONFIG_FS_ROMFS=n
 #   Number of MMC/SD slots supported by the driver
 # CONFIG_MMCSD_READONLY
 #   Provide read-only access (default is read/write)
+# CONFIG_MMCSD_SPICLOCK - Maximum SPI clock to drive MMC/SD card.
+#   Default is 20MHz.
+#
 CONFIG_MMCSD_NSLOTS=1
 CONFIG_MMCSD_READONLY=n
+CONFIG_MMCSD_SPICLOCK=12500000
 
 #
 # TCP/IP and UDP support via uIP