Boot is slow until the bootscreen appears

[jannisl]

Hey guys,

I got a MacPro 5.1 Mid.2010 and have a strange problem. It takes about 20 seconds until the bootscreen appears.

My specs:
3.33Ghz 6-Core Intel Xeon
32GB 1333Mhz DDR3
ATI HD 5770 1024MB

Boot drive: Samsung SSD 850 EVO 250 GB (Sata)
Two original Apple HDDs in RAID (Each 1TB)

What I already tried:
- Reset PRAM
- Unplug everything except Mouse, Keyboard and Display
- Change start volume to the SSD
- Enable Trim on the SSD

The whole OS is really fast and snappy. Everything works great (Except this boot glitch:

)

Is it normal that it takes so long to boot? And how can I fix it?

Thanks,
Jannis

 

[DeltaMac]

Your video shows a line of random garbage appears on the screen. Do you always see that at boot?
Could indicate a problem with the graphics card.
You should try reseating the graphics card.
It's quick, easy, and free - and might actually help...

 

[jannisl]

I did already try this. But it only happens in Sierra so I think it have to be something software related.

 

[dictoresno]

Mine just started doing this too. I'll reboot the machine and the screen will be blank for 30 seconds before the apple logo appears.

I just installed an SSD and was clocking almost 60 seconds in boot time because of the blank screen that wasted 30-35 seconds of that before the regular boot screen appears. After that it's fine.

But last reboot was better, almost perfectly normal.