Oke,
I have the strangest thing, scenario:
2014:
Mac pro 3.1 with it's original ati graphics card, always running fine and upgraded towards el capitan in the years coming.
Did not use windows or anything on it until 2021.
2021:
I upgraded my mac pro 3.1 running el capitan with a radeon 5770 because i needed the display port for a new monitor (ultra wide screen)
After the upgrade to the radeon 5770, i installed win 10 with a dvd on a ssd in drivebay 3 in legacy mode. No problems. Always running fine, can boot with alt in mac os (ssd bay 1) or win 10 (ssd bay 3)
Drive bay 1 ssd El capitan,
Drive bay 2 harddisk data for el capitan
Drive bay 3 ssd win 10 legacy
Drivebay 4 harddisk data for win 10
2023,
I bought a mac pro 5.1 with a gtx 680
Installed mojave on a nvme drive + simple pcie card on pcie slot 3,
Tried installing win 10 on a ssd in drivebay 3, problems and more problems, it just would not boot win 10, until i tried the win 10 ssd in bay 1 and 2, then win 10 would boot!
The mac pro 5.1 can read any harddrive in any drivebay in win and mac os, but it just can't boot win 10 in Bay 3 and 4.
So at that point, i thougt it's a limitation that only affects the mac pro 5.1, and not the mac pro 3.1.
I could live with that.
Oke, 2023 july
I upgraded the mac pro 5.1 with a radeon vega 56, so i have a spare gtx 680.
I upgraded my old mac pro 3.1 with still the same config as in 2021 with the gtx 680 witch I pulled from the mac pro 5.1
With the gtx 680 in the mac pro 3.1 all is running good,
boot mac os El capitan from the ssd in drive bay 1 is working fine.
Boot win 10 from the ssd in drivebay 3 is working fine!
So no problems here, but here it comes.
I took every drivebay out the mac pro 3.1, except drivebay 1 with the ssd. Did the nvram reset 3 times, and started installing a fresh copy of mojave with the dosdude1 patch on the now formatted ssd. All is fine, a working mojave os in drivebay 1, and the old windows 10 ssd in drivebay 3 wich hasn't change untill 2021 is still working.
Ok, from here, I swapped the ssd,s. The win 10 is a 128 gb ssd, the mac os is a 256 gb ssd.
So i started from scratch.
First I installed Catalina on the ssd in drivebay 1, no problems.
After that i installed win 10 on the ssd in drivebay 3,.... I installed it like 6 times. The install procedure gives no problems. But booting afterwards, it just won't boot. Finally I discovered when I put the fresh installed win 10 ssd in drivebay 1 or 2, win 10 will boot and leads me thruw the win 10 post install options.
So, as of now I'm really confused. Why won't win 10 suddenly boot in drivebay 3 and 4?
With the mac pro 5.1 i thougt it was a hardware limitation (strange but what do i know) but now with the mac pro 3.1 i have the same problem so there is something going on here.
OK some more testing,
I have a second spare untouched mac pro 3.1 with El capitan running on a old spinning disk with the old radeon 5770 in it. So i tried my win 10 ssd in drivebay 3 in that mac.
Same problems, it won't boot.
So now I'm thinking this problem with win 10 not booting in drivebay 3 and 4 is related to the vidcards change, i know it's strange, but all this only happened after installing win 10 with a gtx 680 and a vega 56 no matter which mac pro.
When I installed win 10 on a ssd in drivebay 3 in 2021 while running the radeon 5770 i didn't have problems.
Anyway,
I can read harddisks and ssd's in all drivebays in osx and win 10, also the osx boot ssd does boot in all drivebays. it's just that drivebay 3 and 4 won't boot a windows 10 disk.
So in the coming days I will do some more testing with my untouched spare mac pro 3.1, equipped with the radeon 5770. ill do a fresh win 10 install on a ssd in drivebay 3 while drive 1 is occupied with the old el capitan spinning hard drive.
Really can't wrap my head arround this.
Anyone knows about this problem/bug?
I have the strangest thing, scenario:
2014:
Mac pro 3.1 with it's original ati graphics card, always running fine and upgraded towards el capitan in the years coming.
Did not use windows or anything on it until 2021.
2021:
I upgraded my mac pro 3.1 running el capitan with a radeon 5770 because i needed the display port for a new monitor (ultra wide screen)
After the upgrade to the radeon 5770, i installed win 10 with a dvd on a ssd in drivebay 3 in legacy mode. No problems. Always running fine, can boot with alt in mac os (ssd bay 1) or win 10 (ssd bay 3)
Drive bay 1 ssd El capitan,
Drive bay 2 harddisk data for el capitan
Drive bay 3 ssd win 10 legacy
Drivebay 4 harddisk data for win 10
2023,
I bought a mac pro 5.1 with a gtx 680
Installed mojave on a nvme drive + simple pcie card on pcie slot 3,
Tried installing win 10 on a ssd in drivebay 3, problems and more problems, it just would not boot win 10, until i tried the win 10 ssd in bay 1 and 2, then win 10 would boot!
The mac pro 5.1 can read any harddrive in any drivebay in win and mac os, but it just can't boot win 10 in Bay 3 and 4.
So at that point, i thougt it's a limitation that only affects the mac pro 5.1, and not the mac pro 3.1.
I could live with that.
Oke, 2023 july
I upgraded the mac pro 5.1 with a radeon vega 56, so i have a spare gtx 680.
I upgraded my old mac pro 3.1 with still the same config as in 2021 with the gtx 680 witch I pulled from the mac pro 5.1
With the gtx 680 in the mac pro 3.1 all is running good,
boot mac os El capitan from the ssd in drive bay 1 is working fine.
Boot win 10 from the ssd in drivebay 3 is working fine!
So no problems here, but here it comes.
I took every drivebay out the mac pro 3.1, except drivebay 1 with the ssd. Did the nvram reset 3 times, and started installing a fresh copy of mojave with the dosdude1 patch on the now formatted ssd. All is fine, a working mojave os in drivebay 1, and the old windows 10 ssd in drivebay 3 wich hasn't change untill 2021 is still working.
Ok, from here, I swapped the ssd,s. The win 10 is a 128 gb ssd, the mac os is a 256 gb ssd.
So i started from scratch.
First I installed Catalina on the ssd in drivebay 1, no problems.
After that i installed win 10 on the ssd in drivebay 3,.... I installed it like 6 times. The install procedure gives no problems. But booting afterwards, it just won't boot. Finally I discovered when I put the fresh installed win 10 ssd in drivebay 1 or 2, win 10 will boot and leads me thruw the win 10 post install options.
So, as of now I'm really confused. Why won't win 10 suddenly boot in drivebay 3 and 4?
With the mac pro 5.1 i thougt it was a hardware limitation (strange but what do i know) but now with the mac pro 3.1 i have the same problem so there is something going on here.
OK some more testing,
I have a second spare untouched mac pro 3.1 with El capitan running on a old spinning disk with the old radeon 5770 in it. So i tried my win 10 ssd in drivebay 3 in that mac.
Same problems, it won't boot.
So now I'm thinking this problem with win 10 not booting in drivebay 3 and 4 is related to the vidcards change, i know it's strange, but all this only happened after installing win 10 with a gtx 680 and a vega 56 no matter which mac pro.
When I installed win 10 on a ssd in drivebay 3 in 2021 while running the radeon 5770 i didn't have problems.
Anyway,
I can read harddisks and ssd's in all drivebays in osx and win 10, also the osx boot ssd does boot in all drivebays. it's just that drivebay 3 and 4 won't boot a windows 10 disk.
So in the coming days I will do some more testing with my untouched spare mac pro 3.1, equipped with the radeon 5770. ill do a fresh win 10 install on a ssd in drivebay 3 while drive 1 is occupied with the old el capitan spinning hard drive.
Really can't wrap my head arround this.
Anyone knows about this problem/bug?