diff --git a/bootloader/storage/nx_sd.c b/bootloader/storage/nx_sd.c
index 7b9935a..459e30d 100644
--- a/bootloader/storage/nx_sd.c
+++ b/bootloader/storage/nx_sd.c
@@ -23,24 +23,96 @@
 #include "../mem/heap.h"
 
 static bool sd_mounted = false;
+static u32  sd_mode = SD_UHS_SDR82;
+
+u32 sd_mode_get()
+{
+	return sd_mode;
+}
+
+int sd_init_retry(bool power_cycle)
+{
+	u32 bus_width = SDMMC_BUS_WIDTH_4;
+	u32 type = SDHCI_TIMING_UHS_SDR82;
+
+	// Power cycle SD card.
+	if (power_cycle)
+	{
+		sd_mode--;
+		sdmmc_storage_end(&sd_storage);
+	}
+
+	// Get init parameters.
+	switch (sd_mode)
+	{
+	case SD_INIT_FAIL: // Reset to max.
+		return 0;
+	case SD_1BIT_HS25:
+		bus_width = SDMMC_BUS_WIDTH_1;
+		type = SDHCI_TIMING_SD_HS25;
+		break;
+	case SD_4BIT_HS25:
+		type = SDHCI_TIMING_SD_HS25;
+		break;
+	case SD_UHS_SDR82:
+		type = SDHCI_TIMING_UHS_SDR82;
+		break;
+	default:
+		sd_mode = SD_UHS_SDR82;
+	}
+
+	return sdmmc_storage_init_sd(&sd_storage, &sd_sdmmc, bus_width, type);
+}
+
+bool sd_initialize(bool power_cycle)
+{
+	if (power_cycle)
+		sdmmc_storage_end(&sd_storage);
+
+	int res = !sd_init_retry(false);
+
+	while (true)
+	{
+		if (!res)
+			return true;
+		else if (!sdmmc_get_sd_inserted()) // SD Card is not inserted.
+		{
+			sd_mode = SD_UHS_SDR82;
+			break;
+		}
+		else if (sd_mode == SD_INIT_FAIL)
+			break;
+		else
+			res = !sd_init_retry(true);
+	}
+
+	sdmmc_storage_end(&sd_storage);
+
+	return false;
+}
 
 bool sd_mount()
 {
 	if (sd_mounted)
 		return true;
 
-	if (!sdmmc_storage_init_sd(&sd_storage, &sd_sdmmc, SDMMC_BUS_WIDTH_4, SDHCI_TIMING_UHS_SDR82))
+	int res = !sd_initialize(false);
+
+	if (res)
 	{
 		gfx_con.mute = false;
-		EPRINTF("Failed to init SD card.\nMake sure that it is inserted.\nOr that SD reader is properly seated!");
+		EPRINTF("Failed to init SD card.");
+		if (!sdmmc_get_sd_inserted())
+			EPRINTF("Make sure that it is inserted.");
+		else
+			EPRINTF("SD Card Reader is not properly seated!");
 	}
 	else
 	{
-		int res = 0;
 		res = f_mount(&sd_fs, "", 1);
 		if (res == FR_OK)
 		{
-			sd_mounted = 1;
+			sd_mounted = true;
 			return true;
 		}
 		else
@@ -55,6 +127,7 @@ bool sd_mount()
 
 void sd_unmount()
 {
+	sd_mode = SD_UHS_SDR82;
 	if (sd_mounted)
 	{
 		f_mount(NULL, "", 1);
diff --git a/bootloader/storage/nx_sd.h b/bootloader/storage/nx_sd.h
index 0c7826e..4c86db0 100644
--- a/bootloader/storage/nx_sd.h
+++ b/bootloader/storage/nx_sd.h
@@ -22,10 +22,21 @@
 #include "sdmmc_driver.h"
 #include "../libs/fatfs/ff.h"
 
+enum
+{
+	SD_INIT_FAIL  = 0,
+	SD_1BIT_HS25  = 1,
+	SD_4BIT_HS25  = 2,
+	SD_UHS_SDR82  = 3,
+};
+
 sdmmc_t sd_sdmmc;
 sdmmc_storage_t sd_storage;
 FATFS sd_fs;
 
+u32  sd_mode_get();
+int  sd_init_retry(bool power_cycle);
+bool sd_initialize(bool power_cycle);
 bool sd_mount();
 void sd_unmount();
 void *sd_file_read(const char *path, u32 *fsize);
diff --git a/bootloader/storage/sdmmc.c b/bootloader/storage/sdmmc.c
index fc941c8..902d0ca 100644
--- a/bootloader/storage/sdmmc.c
+++ b/bootloader/storage/sdmmc.c
@@ -18,6 +18,7 @@
 #include <string.h>
 #include "sdmmc.h"
 #include "mmc.h"
+#include "nx_sd.h"
 #include "sd.h"
 #include "../../common/memory_map.h"
 #include "../gfx/gfx.h"
@@ -172,25 +173,42 @@ int sdmmc_storage_end(sdmmc_storage_t *storage)
 static int _sdmmc_storage_readwrite(sdmmc_storage_t *storage, u32 sector, u32 num_sectors, void *buf, u32 is_write)
 {
 	u8 *bbuf = (u8 *)buf;
-
+	bool first_reinit = false;
 	while (num_sectors)
 	{
 		u32 blkcnt = 0;
-		//Retry 9 times on error.
-		u32 retries = 10;
+		// Retry 5 times if failed.
+		u32 retries = 5;
 		do
 		{
+reinit_try:
 			if (_sdmmc_storage_readwrite_ex(storage, &blkcnt, sector, MIN(num_sectors, 0xFFFF), bbuf, is_write))
 				goto out;
 			else
 				retries--;
 
-			msleep(100);
+			msleep(50);
 		} while (retries);
 
+		// Disk IO failure! Reinit SD Card to a lower speed.
+		if (storage->sdmmc->id == SDMMC_1)
+		{
+			int res;
+			if (!first_reinit)
+				res = sd_initialize(true);
+			else
+				res = sd_init_retry(true);
+
+			retries = 3;
+			first_reinit = true;
+
+			if (res)
+				goto reinit_try;
+		}
+
 		return 0;
 
-out:;
+out:
 DPRINTF("readwrite: %08X\n", blkcnt);
 		sector += blkcnt;
 		num_sectors -= blkcnt;
diff --git a/nyx/nyx_gui/storage/nx_sd.c b/nyx/nyx_gui/storage/nx_sd.c
index 7251beb..c025e6b 100644
--- a/nyx/nyx_gui/storage/nx_sd.c
+++ b/nyx/nyx_gui/storage/nx_sd.c
@@ -33,6 +33,78 @@ bool sd_get_card_removed()
 	return false;
 }
 
+u32 sd_mode_get()
+{
+	return sd_mode;
+}
+
+int sd_init_retry(bool power_cycle)
+{
+	u32 bus_width = SDMMC_BUS_WIDTH_4;
+	u32 type = SDHCI_TIMING_UHS_SDR104;
+
+	// Power cycle SD card.
+	if (power_cycle)
+	{
+		sd_mode--;
+		sdmmc_storage_end(&sd_storage);
+	}
+
+	// Get init parameters.
+	switch (sd_mode)
+	{
+	case SD_INIT_FAIL: // Reset to max.
+		return 0;
+	case SD_1BIT_HS25:
+		bus_width = SDMMC_BUS_WIDTH_1;
+		type = SDHCI_TIMING_SD_HS25;
+		break;
+	case SD_4BIT_HS25:
+		type = SDHCI_TIMING_SD_HS25;
+		break;
+	case SD_UHS_SDR82:
+		type = SDHCI_TIMING_UHS_SDR82;
+		break;
+	case SD_UHS_SDR104:
+		type = SDHCI_TIMING_UHS_SDR104;
+		break;
+	default:
+		sd_mode = SD_UHS_SDR104;
+	}
+
+	return sdmmc_storage_init_sd(&sd_storage, &sd_sdmmc, bus_width, type);
+}
+
+bool sd_initialize(bool power_cycle)
+{
+	if (power_cycle)
+		sdmmc_storage_end(&sd_storage);
+
+	int res = !sd_init_retry(false);
+
+	while (true)
+	{
+		if (!res)
+			return true;
+		else if (!sdmmc_get_sd_inserted()) // SD Card is not inserted.
+		{
+			sd_mode = SD_UHS_SDR104;
+			break;
+		}
+		else
+		{
+			if (sd_mode == SD_INIT_FAIL)
+				break;
+			else
+				res = !sd_init_retry(true);
+		}
+	}
+
+	sdmmc_storage_end(&sd_storage);
+
+	return false;
+}
+
 bool sd_mount()
 {
 	if (sd_mounted)
@@ -41,19 +113,20 @@ bool sd_mount()
 	int res = 0;
 
 	if (!sd_init_done)
-	{
-		res = !sdmmc_storage_init_sd(&sd_storage, &sd_sdmmc, SDMMC_BUS_WIDTH_4, SDHCI_TIMING_UHS_SDR82);
-		if (!res)
-			sd_init_done = true;
-	}
+		res = !sd_initialize(false);
 
 	if (res)
 	{
-		EPRINTF("Failed to init SD card.\nMake sure that it is inserted.\nOr that SD reader is properly seated!");
+		EPRINTF("Failed to init SD card.");
+		if (!sdmmc_get_sd_inserted())
+			EPRINTF("Make sure that it is inserted.");
+		else
+			EPRINTF("SD Card Reader is not properly seated!");
 	}
 	else
 	{
-		int res = f_mount(&sd_fs, "", 1);
+		sd_init_done = true;
+		res = f_mount(&sd_fs, "", 1);
 		if (res == FR_OK)
 		{
 			sd_mounted = true;
@@ -70,6 +143,9 @@ bool sd_mount()
 
 void sd_unmount(bool deinit)
 {
+	if (sd_mode == SD_INIT_FAIL)
+		sd_mode = SD_UHS_SDR104;
+
 	if (sd_init_done && sd_mounted)
 	{
 		f_mount(NULL, "", 1);
diff --git a/nyx/nyx_gui/storage/nx_sd.h b/nyx/nyx_gui/storage/nx_sd.h
index f9054ed..4698c7f 100644
--- a/nyx/nyx_gui/storage/nx_sd.h
+++ b/nyx/nyx_gui/storage/nx_sd.h
@@ -22,11 +22,23 @@
 #include "sdmmc_driver.h"
 #include "../libs/fatfs/ff.h"
 
+enum
+{
+	SD_INIT_FAIL  = 0,
+	SD_1BIT_HS25  = 1,
+	SD_4BIT_HS25  = 2,
+	SD_UHS_SDR82  = 3,
+	SD_UHS_SDR104 = 4
+};
+
 sdmmc_t sd_sdmmc;
 sdmmc_storage_t sd_storage;
 FATFS sd_fs;
 
 bool sd_get_card_removed();
+u32  sd_get_mode();
+int  sd_init_retry(bool power_cycle);
+bool sd_initialize(bool power_cycle);
 bool sd_mount();
 void sd_unmount(bool deinit);
 void *sd_file_read(const char *path, u32 *fsize);
diff --git a/nyx/nyx_gui/storage/sdmmc.c b/nyx/nyx_gui/storage/sdmmc.c
index 5ce0900..d60129e 100644
--- a/nyx/nyx_gui/storage/sdmmc.c
+++ b/nyx/nyx_gui/storage/sdmmc.c
@@ -18,6 +18,7 @@
 #include <string.h>
 #include "sdmmc.h"
 #include "mmc.h"
+#include "nx_sd.h"
 #include "sd.h"
 #include "../../../common/memory_map.h"
 #include "../gfx/gfx.h"
@@ -172,25 +173,43 @@ int sdmmc_storage_end(sdmmc_storage_t *storage)
 static int _sdmmc_storage_readwrite(sdmmc_storage_t *storage, u32 sector, u32 num_sectors, void *buf, u32 is_write)
 {
 	u8 *bbuf = (u8 *)buf;
-
+	bool first_reinit = false;
 	while (num_sectors)
 	{
 		u32 blkcnt = 0;
-		//Retry 9 times on error.
-		u32 retries = 10;
+		// Retry 5 times if failed.
+		u32 retries = 5;
 		do
 		{
+reinit_try:
 			if (_sdmmc_storage_readwrite_ex(storage, &blkcnt, sector, MIN(num_sectors, 0xFFFF), bbuf, is_write))
 				goto out;
 			else
 				retries--;
 
-			msleep(100);
+			msleep(50);
 		} while (retries);
 
+		// Disk IO failure! Reinit SD Card to a lower speed.
+		if (storage->sdmmc->id == SDMMC_1)
+		{
+			int res;
+
+			if (!first_reinit)
+				res = sd_initialize(true);
+			else
+				res = sd_init_retry(true);
+
+			retries = 3;
+			first_reinit = true;
+
+			if (res)
+				goto reinit_try;
+		}
+
 		return 0;
 
-out:;
+out:
 DPRINTF("readwrite: %08X\n", blkcnt);
 		sector += blkcnt;
 		num_sectors -= blkcnt;