diff --git a/Marlin/Configuration.h b/Marlin/Configuration.h
index 6b3dd0d7e6..7c1009e09c 100644
--- a/Marlin/Configuration.h
+++ b/Marlin/Configuration.h
@@ -667,6 +667,7 @@ const bool Z_MIN_PROBE_ENDSTOP_INVERTING = false; // set to true to invert the l
 //#define DOGLCD  // Support for SPI LCD 128x64 (Controller ST7565R graphic Display Family)
 //#define SDSUPPORT // Enable SD Card Support in Hardware Console
 //#define SDSLOW // Use slower SD transfer mode (not normally needed - uncomment if you're getting volume init error)
+//#define SDEXTRASLOW // Use even slower SD transfer mode (not normally needed - uncomment if you're getting volume init error)
 //#define SD_CHECK_AND_RETRY // Use CRC checks and retries on the SD communication
 //#define ENCODER_PULSES_PER_STEP 1 // Increase if you have a high resolution encoder
 //#define ENCODER_STEPS_PER_MENU_ITEM 5 // Set according to ENCODER_PULSES_PER_STEP or your liking
diff --git a/Marlin/cardreader.cpp b/Marlin/cardreader.cpp
index 8bb22c8a2f..2fcd0c4b68 100644
--- a/Marlin/cardreader.cpp
+++ b/Marlin/cardreader.cpp
@@ -195,7 +195,9 @@ void CardReader::initsd() {
   cardOK = false;
   if (root.isOpen()) root.close();
 
-  #if ENABLED(SDSLOW)
+  #if ENABLED(SDEXTRASLOW)
+    #define SPI_SPEED SPI_QUARTER_SPEED
+  #elif ENABLED(SDSLOW)
     #define SPI_SPEED SPI_HALF_SPEED
   #else
     #define SPI_SPEED SPI_FULL_SPEED
diff --git a/Marlin/configurator/config/Configuration.h b/Marlin/configurator/config/Configuration.h
index 4ba6dd2eae..ec7f0969db 100644
--- a/Marlin/configurator/config/Configuration.h
+++ b/Marlin/configurator/config/Configuration.h
@@ -666,6 +666,7 @@ const bool Z_MIN_PROBE_ENDSTOP_INVERTING = false; // set to true to invert the l
 //#define DOGLCD  // Support for SPI LCD 128x64 (Controller ST7565R graphic Display Family)
 //#define SDSUPPORT // Enable SD Card Support in Hardware Console
 //#define SDSLOW // Use slower SD transfer mode (not normally needed - uncomment if you're getting volume init error)
+//#define SDEXTRASLOW // Use even slower SD transfer mode (not normally needed - uncomment if you're getting volume init error)
 //#define SD_CHECK_AND_RETRY // Use CRC checks and retries on the SD communication
 //#define ENCODER_PULSES_PER_STEP 1 // Increase if you have a high resolution encoder
 //#define ENCODER_STEPS_PER_MENU_ITEM 5 // Set according to ENCODER_PULSES_PER_STEP or your liking
diff --git a/Marlin/example_configurations/Felix/Configuration.h b/Marlin/example_configurations/Felix/Configuration.h
index 4f9ce10ce0..b5543e3d92 100644
--- a/Marlin/example_configurations/Felix/Configuration.h
+++ b/Marlin/example_configurations/Felix/Configuration.h
@@ -649,6 +649,7 @@ const bool Z_MIN_PROBE_ENDSTOP_INVERTING = false; // set to true to invert the l
 //#define DOGLCD  // Support for SPI LCD 128x64 (Controller ST7565R graphic Display Family)
 //#define SDSUPPORT // Enable SD Card Support in Hardware Console
 //#define SDSLOW // Use slower SD transfer mode (not normally needed - uncomment if you're getting volume init error)
+//#define SDEXTRASLOW // Use even slower SD transfer mode (not normally needed - uncomment if you're getting volume init error)
 //#define SD_CHECK_AND_RETRY // Use CRC checks and retries on the SD communication
 //#define ENCODER_PULSES_PER_STEP 1 // Increase if you have a high resolution encoder
 //#define ENCODER_STEPS_PER_MENU_ITEM 5 // Set according to ENCODER_PULSES_PER_STEP or your liking
diff --git a/Marlin/example_configurations/Felix/Configuration_DUAL.h b/Marlin/example_configurations/Felix/Configuration_DUAL.h
index d9586d7b2f..672e05446f 100644
--- a/Marlin/example_configurations/Felix/Configuration_DUAL.h
+++ b/Marlin/example_configurations/Felix/Configuration_DUAL.h
@@ -618,6 +618,7 @@ const bool Z_MIN_PROBE_ENDSTOP_INVERTING = false; // set to true to invert the l
 //#define DOGLCD  // Support for SPI LCD 128x64 (Controller ST7565R graphic Display Family)
 //#define SDSUPPORT // Enable SD Card Support in Hardware Console
 //#define SDSLOW // Use slower SD transfer mode (not normally needed - uncomment if you're getting volume init error)
+//#define SDEXTRASLOW // Use even slower SD transfer mode (not normally needed - uncomment if you're getting volume init error)
 //#define SD_CHECK_AND_RETRY // Use CRC checks and retries on the SD communication
 //#define ENCODER_PULSES_PER_STEP 1 // Increase if you have a high resolution encoder
 //#define ENCODER_STEPS_PER_MENU_ITEM 5 // Set according to ENCODER_PULSES_PER_STEP or your liking
diff --git a/Marlin/example_configurations/Hephestos/Configuration.h b/Marlin/example_configurations/Hephestos/Configuration.h
index 3811129b71..c6fcee8371 100644
--- a/Marlin/example_configurations/Hephestos/Configuration.h
+++ b/Marlin/example_configurations/Hephestos/Configuration.h
@@ -659,6 +659,7 @@ const bool Z_MIN_PROBE_ENDSTOP_INVERTING = true; // set to true to invert the lo
 //#define DOGLCD  // Support for SPI LCD 128x64 (Controller ST7565R graphic Display Family)
 #define SDSUPPORT // Enable SD Card Support in Hardware Console
 //#define SDSLOW // Use slower SD transfer mode (not normally needed - uncomment if you're getting volume init error)
+//#define SDEXTRASLOW // Use even slower SD transfer mode (not normally needed - uncomment if you're getting volume init error)
 //#define SD_CHECK_AND_RETRY // Use CRC checks and retries on the SD communication
 //#define ENCODER_PULSES_PER_STEP 1 // Increase if you have a high resolution encoder
 //#define ENCODER_STEPS_PER_MENU_ITEM 5 // Set according to ENCODER_PULSES_PER_STEP or your liking
diff --git a/Marlin/example_configurations/K8200/Configuration.h b/Marlin/example_configurations/K8200/Configuration.h
index 5eec325e48..5d4734ee36 100644
--- a/Marlin/example_configurations/K8200/Configuration.h
+++ b/Marlin/example_configurations/K8200/Configuration.h
@@ -654,6 +654,7 @@ const bool Z_MIN_PROBE_ENDSTOP_INVERTING = false; // set to true to invert the l
 //#define DOGLCD  // Support for SPI LCD 128x64 (Controller ST7565R graphic Display Family)
 //#define SDSUPPORT // Enable SD Card Support in Hardware Console
 //#define SDSLOW // Use slower SD transfer mode (not normally needed - uncomment if you're getting volume init error)
+//#define SDEXTRASLOW // Use even slower SD transfer mode (not normally needed - uncomment if you're getting volume init error)
 //#define SD_CHECK_AND_RETRY // Use CRC checks and retries on the SD communication
 //#define ENCODER_PULSES_PER_STEP 1 // Increase if you have a high resolution encoder
 //#define ENCODER_STEPS_PER_MENU_ITEM 5 // Set according to ENCODER_PULSES_PER_STEP or your liking
diff --git a/Marlin/example_configurations/RepRapWorld/Megatronics/Configuration.h b/Marlin/example_configurations/RepRapWorld/Megatronics/Configuration.h
index 79d001a451..6f7e7e1c74 100644
--- a/Marlin/example_configurations/RepRapWorld/Megatronics/Configuration.h
+++ b/Marlin/example_configurations/RepRapWorld/Megatronics/Configuration.h
@@ -667,6 +667,7 @@ const bool Z_MIN_PROBE_ENDSTOP_INVERTING = false; // set to true to invert the l
 //#define DOGLCD  // Support for SPI LCD 128x64 (Controller ST7565R graphic Display Family)
 #define SDSUPPORT // Enable SD Card Support in Hardware Console
 //#define SDSLOW // Use slower SD transfer mode (not normally needed - uncomment if you're getting volume init error)
+//#define SDEXTRASLOW // Use even slower SD transfer mode (not normally needed - uncomment if you're getting volume init error)
 #define SD_CHECK_AND_RETRY // Use CRC checks and retries on the SD communication
 //#define ENCODER_PULSES_PER_STEP 1 // Increase if you have a high resolution encoder
 //#define ENCODER_STEPS_PER_MENU_ITEM 5 // Set according to ENCODER_PULSES_PER_STEP or your liking
diff --git a/Marlin/example_configurations/RigidBot/Configuration.h b/Marlin/example_configurations/RigidBot/Configuration.h
index 105b0521ef..2369b878f5 100644
--- a/Marlin/example_configurations/RigidBot/Configuration.h
+++ b/Marlin/example_configurations/RigidBot/Configuration.h
@@ -653,6 +653,7 @@ const bool Z_MIN_PROBE_ENDSTOP_INVERTING = false; // set to true to invert the l
 //#define DOGLCD  // Support for SPI LCD 128x64 (Controller ST7565R graphic Display Family)
 //#define SDSUPPORT // Enable SD Card Support in Hardware Console
 //#define SDSLOW // Use slower SD transfer mode (not normally needed - uncomment if you're getting volume init error)
+//#define SDEXTRASLOW // Use even slower SD transfer mode (not normally needed - uncomment if you're getting volume init error)
 //#define SD_CHECK_AND_RETRY // Use CRC checks and retries on the SD communication
 //#define ENCODER_PULSES_PER_STEP 1 // Increase if you have a high resolution encoder
 //#define ENCODER_STEPS_PER_MENU_ITEM 5 // Set according to ENCODER_PULSES_PER_STEP or your liking
diff --git a/Marlin/example_configurations/SCARA/Configuration.h b/Marlin/example_configurations/SCARA/Configuration.h
index e7b9f182d6..0738512ef2 100644
--- a/Marlin/example_configurations/SCARA/Configuration.h
+++ b/Marlin/example_configurations/SCARA/Configuration.h
@@ -674,6 +674,7 @@ const bool Z_MIN_PROBE_ENDSTOP_INVERTING = false; // set to true to invert the l
 //#define DOGLCD  // Support for SPI LCD 128x64 (Controller ST7565R graphic Display Family)
 //#define SDSUPPORT // Enable SD Card Support in Hardware Console
 //#define SDSLOW // Use slower SD transfer mode (not normally needed - uncomment if you're getting volume init error)
+//#define SDEXTRASLOW // Use even slower SD transfer mode (not normally needed - uncomment if you're getting volume init error)
 //#define SD_CHECK_AND_RETRY // Use CRC checks and retries on the SD communication
 //#define ENCODER_PULSES_PER_STEP 1 // Increase if you have a high resolution encoder
 //#define ENCODER_STEPS_PER_MENU_ITEM 5 // Set according to ENCODER_PULSES_PER_STEP or your liking
diff --git a/Marlin/example_configurations/TAZ4/Configuration.h b/Marlin/example_configurations/TAZ4/Configuration.h
index b264b36cad..cf52f9c3c1 100644
--- a/Marlin/example_configurations/TAZ4/Configuration.h
+++ b/Marlin/example_configurations/TAZ4/Configuration.h
@@ -685,6 +685,7 @@ const bool Z_MIN_PROBE_ENDSTOP_INVERTING = false; // set to true to invert the l
 //#define DOGLCD  // Support for SPI LCD 128x64 (Controller ST7565R graphic Display Family)
 //#define SDSUPPORT // Enable SD Card Support in Hardware Console
 //#define SDSLOW // Use slower SD transfer mode (not normally needed - uncomment if you're getting volume init error)
+//#define SDEXTRASLOW // Use even slower SD transfer mode (not normally needed - uncomment if you're getting volume init error)
 //#define SD_CHECK_AND_RETRY // Use CRC checks and retries on the SD communication
 #define ENCODER_PULSES_PER_STEP 2 // Increase if you have a high resolution encoder
 #define ENCODER_STEPS_PER_MENU_ITEM 1 // Set according to ENCODER_PULSES_PER_STEP or your liking
diff --git a/Marlin/example_configurations/WITBOX/Configuration.h b/Marlin/example_configurations/WITBOX/Configuration.h
index 1728d19b65..720aff139e 100644
--- a/Marlin/example_configurations/WITBOX/Configuration.h
+++ b/Marlin/example_configurations/WITBOX/Configuration.h
@@ -658,6 +658,7 @@ const bool Z_MIN_PROBE_ENDSTOP_INVERTING = true; // set to true to invert the lo
 //#define DOGLCD  // Support for SPI LCD 128x64 (Controller ST7565R graphic Display Family)
 #define SDSUPPORT // Enable SD Card Support in Hardware Console
 //#define SDSLOW // Use slower SD transfer mode (not normally needed - uncomment if you're getting volume init error)
+//#define SDEXTRASLOW // Use even slower SD transfer mode (not normally needed - uncomment if you're getting volume init error)
 //#define SD_CHECK_AND_RETRY // Use CRC checks and retries on the SD communication
 //#define ENCODER_PULSES_PER_STEP 1 // Increase if you have a high resolution encoder
 //#define ENCODER_STEPS_PER_MENU_ITEM 5 // Set according to ENCODER_PULSES_PER_STEP or your liking
diff --git a/Marlin/example_configurations/adafruit/ST7565/Configuration.h b/Marlin/example_configurations/adafruit/ST7565/Configuration.h
index 031cceb4f1..3d72a5fd34 100644
--- a/Marlin/example_configurations/adafruit/ST7565/Configuration.h
+++ b/Marlin/example_configurations/adafruit/ST7565/Configuration.h
@@ -667,6 +667,7 @@ const bool Z_MIN_PROBE_ENDSTOP_INVERTING = false; // set to true to invert the l
 //#define DOGLCD  // Support for SPI LCD 128x64 (Controller ST7565R graphic Display Family)
 #define SDSUPPORT // Enable SD Card Support in Hardware Console
 #define SDSLOW // Use slower SD transfer mode (not normally needed - uncomment if you're getting volume init error)
+//#define SDEXTRASLOW // Use even slower SD transfer mode (not normally needed - uncomment if you're getting volume init error)
 //#define SD_CHECK_AND_RETRY // Use CRC checks and retries on the SD communication
 //#define ENCODER_PULSES_PER_STEP 1 // Increase if you have a high resolution encoder
 //#define ENCODER_STEPS_PER_MENU_ITEM 5 // Set according to ENCODER_PULSES_PER_STEP or your liking
diff --git a/Marlin/example_configurations/delta/biv2.5/Configuration.h b/Marlin/example_configurations/delta/biv2.5/Configuration.h
index ba2abe1cb6..fb77c1edaa 100644
--- a/Marlin/example_configurations/delta/biv2.5/Configuration.h
+++ b/Marlin/example_configurations/delta/biv2.5/Configuration.h
@@ -788,6 +788,7 @@ const bool Z_MIN_PROBE_ENDSTOP_INVERTING = true; // set to true to invert the lo
 //#define DOGLCD  // Support for SPI LCD 128x64 (Controller ST7565R graphic Display Family)
 //#define SDSUPPORT // Enable SD Card Support in Hardware Console
 //#define SDSLOW // Use slower SD transfer mode (not normally needed - uncomment if you're getting volume init error)
+//#define SDEXTRASLOW // Use even slower SD transfer mode (not normally needed - uncomment if you're getting volume init error)
 //#define SD_CHECK_AND_RETRY // Use CRC checks and retries on the SD communication
 //#define ENCODER_PULSES_PER_STEP 1 // Increase if you have a high resolution encoder
 //#define ENCODER_STEPS_PER_MENU_ITEM 5 // Set according to ENCODER_PULSES_PER_STEP or your liking
diff --git a/Marlin/example_configurations/delta/generic/Configuration.h b/Marlin/example_configurations/delta/generic/Configuration.h
index c5250811dd..7a6bf66e1d 100644
--- a/Marlin/example_configurations/delta/generic/Configuration.h
+++ b/Marlin/example_configurations/delta/generic/Configuration.h
@@ -789,6 +789,7 @@ const bool Z_MIN_PROBE_ENDSTOP_INVERTING = true; // set to true to invert the lo
 //#define DOGLCD  // Support for SPI LCD 128x64 (Controller ST7565R graphic Display Family)
 //#define SDSUPPORT // Enable SD Card Support in Hardware Console
 //#define SDSLOW // Use slower SD transfer mode (not normally needed - uncomment if you're getting volume init error)
+//#define SDEXTRASLOW // Use even slower SD transfer mode (not normally needed - uncomment if you're getting volume init error)
 //#define SD_CHECK_AND_RETRY // Use CRC checks and retries on the SD communication
 //#define ENCODER_PULSES_PER_STEP 1 // Increase if you have a high resolution encoder
 //#define ENCODER_STEPS_PER_MENU_ITEM 5 // Set according to ENCODER_PULSES_PER_STEP or your liking
diff --git a/Marlin/example_configurations/delta/kossel_mini/Configuration.h b/Marlin/example_configurations/delta/kossel_mini/Configuration.h
index 2c8c28310f..5f47f1baa4 100644
--- a/Marlin/example_configurations/delta/kossel_mini/Configuration.h
+++ b/Marlin/example_configurations/delta/kossel_mini/Configuration.h
@@ -793,6 +793,7 @@ const bool Z_MIN_PROBE_ENDSTOP_INVERTING = false; // set to true to invert the l
 //#define DOGLCD  // Support for SPI LCD 128x64 (Controller ST7565R graphic Display Family)
 //#define SDSUPPORT // Enable SD Card Support in Hardware Console
 //#define SDSLOW // Use slower SD transfer mode (not normally needed - uncomment if you're getting volume init error)
+//#define SDEXTRASLOW // Use even slower SD transfer mode (not normally needed - uncomment if you're getting volume init error)
 //#define SD_CHECK_AND_RETRY // Use CRC checks and retries on the SD communication
 //#define ENCODER_PULSES_PER_STEP 1 // Increase if you have a high resolution encoder
 //#define ENCODER_STEPS_PER_MENU_ITEM 5 // Set according to ENCODER_PULSES_PER_STEP or your liking
diff --git a/Marlin/example_configurations/delta/kossel_pro/Configuration.h b/Marlin/example_configurations/delta/kossel_pro/Configuration.h
index 703e07d84a..b484a2dccf 100644
--- a/Marlin/example_configurations/delta/kossel_pro/Configuration.h
+++ b/Marlin/example_configurations/delta/kossel_pro/Configuration.h
@@ -784,6 +784,7 @@ const bool Z_MIN_PROBE_ENDSTOP_INVERTING = false; // set to true to invert the l
 //#define DOGLCD  // Support for SPI LCD 128x64 (Controller ST7565R graphic Display Family)
 #define SDSUPPORT // Enable SD Card Support in Hardware Console
 //#define SDSLOW // Use slower SD transfer mode (not normally needed - uncomment if you're getting volume init error)
+//#define SDEXTRASLOW // Use even slower SD transfer mode (not normally needed - uncomment if you're getting volume init error)
 //#define SD_CHECK_AND_RETRY // Use CRC checks and retries on the SD communication
 //#define ENCODER_PULSES_PER_STEP 1 // Increase if you have a high resolution encoder
 //#define ENCODER_STEPS_PER_MENU_ITEM 5 // Set according to ENCODER_PULSES_PER_STEP or your liking
diff --git a/Marlin/example_configurations/makibox/Configuration.h b/Marlin/example_configurations/makibox/Configuration.h
index b5fb7567ed..7dc984e71c 100644
--- a/Marlin/example_configurations/makibox/Configuration.h
+++ b/Marlin/example_configurations/makibox/Configuration.h
@@ -669,6 +669,7 @@ const bool Z_MIN_PROBE_ENDSTOP_INVERTING = false; // set to true to invert the l
 //#define DOGLCD  // Support for SPI LCD 128x64 (Controller ST7565R graphic Display Family)
 #define SDSUPPORT // Enable SD Card Support in Hardware Console
 #define SDSLOW // Use slower SD transfer mode (not normally needed - uncomment if you're getting volume init error)
+//#define SDEXTRASLOW // Use even slower SD transfer mode (not normally needed - uncomment if you're getting volume init error)
 //#define SD_CHECK_AND_RETRY // Use CRC checks and retries on the SD communication
 //#define ENCODER_PULSES_PER_STEP 1 // Increase if you have a high resolution encoder
 //#define ENCODER_STEPS_PER_MENU_ITEM 5 // Set according to ENCODER_PULSES_PER_STEP or your liking
diff --git a/Marlin/example_configurations/tvrrug/Round2/Configuration.h b/Marlin/example_configurations/tvrrug/Round2/Configuration.h
index 4e349dec40..eee2edc173 100644
--- a/Marlin/example_configurations/tvrrug/Round2/Configuration.h
+++ b/Marlin/example_configurations/tvrrug/Round2/Configuration.h
@@ -661,6 +661,7 @@ const bool Z_MIN_PROBE_ENDSTOP_INVERTING = true; // set to true to invert the lo
 //#define DOGLCD  // Support for SPI LCD 128x64 (Controller ST7565R graphic Display Family)
 //#define SDSUPPORT // Enable SD Card Support in Hardware Console
 //#define SDSLOW // Use slower SD transfer mode (not normally needed - uncomment if you're getting volume init error)
+//#define SDEXTRASLOW // Use even slower SD transfer mode (not normally needed - uncomment if you're getting volume init error)
 //#define SD_CHECK_AND_RETRY // Use CRC checks and retries on the SD communication
 //#define ENCODER_PULSES_PER_STEP 1 // Increase if you have a high resolution encoder
 //#define ENCODER_STEPS_PER_MENU_ITEM 5 // Set according to ENCODER_PULSES_PER_STEP or your liking