Progressbar hangs when booting the Mac Pro under Sierra

[Mac Hammer Fan]

I have two Mac Pro's 2009 5,1 that I upgraded to High Sierra on a SSD. However on the first I work most of the time with Sierra and on the second most with Yosemite on another SSD. I only have problems with the first Mac. After the startup chime it takes more than 30 seconds before I hear disk activity and then the computer boots. The Mac can't find the startup disk immediately although it is selected in the control panel "Startup disk". The Mac has 32 GB RAM, an nVidia Geforce 980 in slot 1, a GT 120 in slot 2, an USB card in slot 3 and an OWC Accelsior SATA III PCI card in slot 4 with a Samsung 850 EVO SSD 512 GB. The problem first occurred after I installed High Sierra on an internal SSD in the second hard drive bay. (HFS+ formatted) But it went away after some reboots. Now it is back. It only occurs when I boot from Sierra on the Tempo SSD in slot 4 and not always it takes even long.
I have a second Mac Pro with a Radeon 5870 in slot 1, a Sonnet PCI-e SSD in slot 2, a Caldigit USB 3 card in slot 3 and an OWC Accelsior PCI SATA III card with a Samsung EVO SSD in slot 4. The drive bays all contain harddrives. On this Mac there is no problem.
I zapped the PRAM but on the first Mac but the problem wasn't solved. Also, when I open the startup disk control panel and choose a different disk, I get a message "Insufficient Priveleges". I can't reboot correctly from the startup disk control panel but well from the commando in the finder.
Can someone give me advice? I haven't tried an SMC reset.
TIA

 

[h9826790]

Sounds like some permission issue, did you try disk utility-> first aid?

Since you have a GT120. I recommend you try that in recovery partition.

 

[Mac Hammer Fan]

Last time I booted the Mac today it took 90 seconds. It's getting worse. According to disk utility all volumes appear to be OK. Since there were no problems found, I didn't try this in the recovery partition yet.
Perhaps I need a new PRAM Battery?
3 V CR2032 lithium ?

 

[h9826790]

Last time I booted the Mac today it took 90 seconds. It's getting worse. According to disk utility all volumes appear to be OK. Since there were no problems found, I didn't try this in the recovery partition yet.
Perhaps I need a new PRAM Battery?
3 V CR2032 lithium ?

Swap the battery between the Macs, then you may know the answer.

 

[Mac Hammer Fan]

I will buy a new battery, it's only 2,5 EUR. But the strange thing is that my Mac Pro boots fast under High Sierra on an OWC Neptune SSD in a drive bay. So I am not sure that the PRAM battery is the culprit. Perhaps there is something wrong with the OWC Accelsior PCI SATA III card where a Samsung EVO 850 SSD with Sierra is installed...

 

[Mac Hammer Fan]

UPDATE: the title of the thread is incorrect. The Mac finds the startup disk immediately but the progressbar hangs for sometimes 90 seconds when it has reached 4/5. I discovered this by switching to a video card that has a bootscreen. (GT120 vs GFX 980). I booted in the safe mode, used CleanMyMac and repaired all the disks in the recovery mode using disk utility. No problems were found.
Now the Sierra partition boots fast. Fingers crossed.

 

[AidenShaw]

UPDATE: the title of the thread is incorrect. The Mac finds the startup disk immediately but the progressbar hangs for sometimes 90 seconds when it has reached 4/5. I discovered this by switching to a video card that has a bootscreen. (GT120 vs GFX 980). I booted in the safe mode, used CleanMyMac and repaired all the disks in the recovery mode using disk utility. No problems were found.
Now the Sierra partition boots fast. Fingers crossed.

The OP can edit the title of the thread. Look above the upper right corner of the first post - and there will be a small icon that will let you edit the title.

 

[Mac Hammer Fan]

Thanks h9826790 and AidenShaw.