Just in case you didn't follow the news, USB Boot firmware for Raspberry Pi 4 Model B is now officially being released as a stable version. Check out this video by Jeff Geerling talking about the stable release of this firmware:
We, at Cytron Technologies, are pretty excited with the stable release of USB boot firmware and are getting reliable and affordable tools needed to enable the USB boot. This is a USB 3.0 to SATA III Adapter with cable, suitable for 2.5" SATA SSD or HDD. We have tried it on Phidisk PhantomKnight II SATA III (6.0 Gbps) 120GB SSD. Install the Raspberry Pi OS and boot it from USB3.0 port on Raspberry Pi 4 Model B.
It boots up without a problem and it is faster than booting from the microSD card. Here is the diagnostic result that we get using Raspberry Pi Diagnostics: (SSD is connected to Raspberry Pi through this adapter to USB3.0 port)
![](https://www.cytron.io/image/catalog/products/CA-USB3-SATA2P5/CA-USB3-SATA2P5_Diagnos_a.jpg )
- Sequential write speed 117237 KB/sec (target 10000) - PASS, nearly 11 times faster than the target
- Random write speed 14209 IOPS (target 500) - PASS, nearly 30 times faster than the target
- Random read speed 13967 IOPS (target 1500) - PASS, nearly 9 times faster than the target
Note: Raspberry Pi Diagnosis result depends on many factors (New memory or used memory, interface, SATA interface, USB interface, USB cable, etc). It should be taken as a reference only.
Of course, the Raspberry Pi 4 Model B must be configured to be able to boot from USB. Not sure your Raspberry Pi 4B is ready for USB boot? Check these steps out:
Option 1: Do it from Raspberry Pi OS desktop with a monitor, keyboard, and mouse, going into the raspi_config, by leepspvideo:
Option 2: Format a blank microSD card (you need to back up in case you have only one microSD card) into FAT32, load the RPi4 EEPROM firmware using Raspberry Pi Imager(download from here). From Operating System->Misc Utility Images->Raspberry Pi 4 EEPROM boot recovery, choose your microSD card and load the image into it:
![](https://www.cytron.io/image/catalog/products/MMR-SSD-P120G/RPi_Imager_Utility_b.jpg )
After the Raspberry Pi Imager loaded the EEPROM firmware into the microSD card, insert it into your Raspberry Pi 4B microSD card slot and power it up. After just 3 seconds, the EEPROM is updated with new firmware and it is ready for USB boot.
Option 3: Boot it directly if your Raspberry Pi 4B comes with the latest firmware in the EEPROM, nothing needed to be updated :)
Warranty Period: 12 months