Progressbar hangs when booting the Mac Pro under Sierra

i have 2 mac pro's 2009 5,1 upgraded high sierra on ssd. on first work of time sierra , on second yosemite on ssd. have problems first mac. after startup chime takes more 30 seconds before hear disk activity , computer boots. mac can't find startup disk although selected in control panel "startup disk". mac has 32 gb ram, nvidia geforce 980 in slot 1, gt 120 in slot 2, usb card in slot 3 , owc accelsior sata iii pci card in slot 4 samsung 850 evo ssd 512 gb. problem first occurred after installed high sierra on internal ssd in second hard drive bay. (hfs+ formatted) went away after reboots. back. occurs when boot sierra on tempo ssd in slot 4 , not takes long.
have second mac pro radeon 5870 in slot 1, sonnet pci-e ssd in slot 2, caldigit usb 3 card in slot 3 , owc accelsior pci sata iii card samsung evo ssd in slot 4. drive bays contain harddrives. on mac there no problem.
zapped pram on first mac problem wasn't solved. also, when open startup disk control panel , choose different disk, message "insufficient priveleges". can't reboot correctly startup disk control panel commando in finder.
can give me advice? haven't tried smc reset.
tia

 

sounds permission issue, did try disk utility-> first aid?

since have gt120. recommend try in recovery partition.

 

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