Super slow drive speeds on UFS(universal flash storage)

I recently installed Debian 12 on my Acer Chromebook Plus 515 cb515-2h and it works but the boot time is almost 5 minutes. I first thought it was grub but then I read that grub uses the system firmware’s driver to boot the drive. When booting the OS using an external Samsung T7 SSD it works perfectly fine which means the problem lies with the internal UFS 3.1 drive which can reach write speeds up to 1500mbp/s. It definitely isn’t reaching this speed with a 5 minute boot time. I don’t often restart my device but I would like to know if there is a fix.

I have a feeling it’s a problem with your UFS thing and not a Chromebook problem. Did you test the UFS thing on a differnet device?

I personally don’t have this model - but have had other models with removable UFS drives – if you can swap it out with regular nvme one - i would.
UFS is now superseding eMMCs, but some units have UFS on a nvme stick (otherwise its soldered on there

If you can’t replace it - make sure you’re on the latest firmware version - I know MrChromebox recently added support for UFS devices on latest one.

The UFS drive is fine. I tested the speed in another environment booted from an external drive. It reached write speeds of 734 megabytes /s so I don’t see why it is taking so long to boot.

I looked in the computer. Apparently there is a spot for an M.2 SSD but the UFS appears to soldiered onto the motherboard. Are m.2 SSDs supported?

So I manually compiled the firmware from the instructions here: Compiling Custom Firmware | Chrultrabook Docs and it seems to be working better. The boot time is around 45 sec to 2 min. It’s not good but it works.