macpro3,1 macOS10.15.4

The machine has been booting to recovery mode pretty consistently and alarmingly.

So I thought there is something wrong with the file system or something.  But I have a hunch.

So I removed the SSD from the drive bay 1 totally.  And surprise, the mac still boots up what I think it's the recovery mode.  It asks for Language that goes to Utilities.  Apparently the recovery mode is running off entirely from its own, probably from the Time Machine's recovery I imagine but I don't know.

I plugged back the SSD to the optical bay drive via the secret SATA port and power.

Bang, the system goes back to regular login with 10.15.4

So something is wrong with drive bay 1 or how things are connected together I guess.

There are lots of strange thing that I never thought make sense or a difference but it does.

Now the GTX 770 is working the way I expect it to work.  The sleep and wake up seems alright.

At some point I was prepared to make another bootable USB stick to re-install macOS.  The strange thing is I made the stick on my MBP and when I plugged the stick to my MacPro, it doesn't recognize it in recovery....

Too many things I can't explain.

If overnight, the system still boots OK, I will try to reconnect the Blu-ray drive.