Z68x/Sandy Bridge i7 - old hardware install viability

[reppie]

Hi,

I have an El Cap (4 years old probably) install on a PC I built 8 years ago, but there's so many apps that need at least 10.12 now I've got to update, but the High Sierra install app isn't available from the app store so it has to be Mojave so it might as well be Catalina. I'm happy to buy a new GPU but don't want to build a completely new Hack yet. I've got:

Z68x-UDH3-B3 rev 1.0 (F10 EFI BIOS)
i7-2600k Sandy Bridge @ 3.4Ghz
16GB Corsair RAM @ 1333Mhz
Gigabyte GTX 660 OC 2GB (GK106 so will need to be replaced)

And a new SSD to install in to.

Is there any reason why this config with a compatible GPU won't run Catalina? I'm thinking of buying a second-hand GTX 780 or something (https://dortania.github.io/GPU-Buyers-Guide/modern-gpus/nvidia-gpu.html#kepler-series-gtx-6xx-7xx). The current definition is Mac Pro 3,1 I think :/

Can I use EFI or do I need to flash the BIOS to UEFI as a minimum - but then there's compatibility issues with some AMD GPUs I've read, and I'm also concerned about banjaxing the MB and not being able to switch to my current HD install as a backup during the tinkering phase, as this is my primary work machine.

Any info/links would be helpful.

Thanks

 

[trs96]

The current definition is Mac Pro 3,1 I think

MP 3,1 won't work with Catalina. iMac 14,2 will work but won't work with Big Sur if you plan on upgrading to that later. iMac 15,1 or MP 6,1 are still supported by Big Sur. Plan accordingly.

Can I use EFI or do I need to flash the BIOS to UEFI as a minimum

If you want to continue legacy booting that is possible. UEFI does offer many advantages that you should research before making that decision. https://www.gigabyte.com/Motherboard/GA-Z68X-UD3H-B3-rev-10/support#support-dl-bios

I would flash to U1n for the UEFI booting option and use OpenCore bootloader but those are personal choices for you to make. It takes some time to use and learn OC. If you don't want to change, keep using Clover and booting legacy. Then your older El Capitan drive will still work as is with no BIOS changes.

 

[trs96]

I've got to update, but the High Sierra install app isn't available from the app store so it has to be Mojave so it might as well be Catalina.

You can still download HS by using the gibMacOS script. See the Catalina desktop guides forum. It's pinned right at the top of that.

 

[reppie]

MP 3,1 won't work with Catalina. iMac 14,2 will work but won't work with Big Sur if you plan on upgrading to that later. iMac 15,1 or MP 6,1 are still supported by Big Sur. Plan accordingly.

If you want to continue legacy booting that is possible. UEFI does offer many advantages that you should research before making that decision. https://www.gigabyte.com/Motherboard/GA-Z68X-UD3H-B3-rev-10/support#support-dl-bios

I would flash to U1n for the UEFI booting option and use OpenCore bootloader but those are personal choices for you to make. It takes some time to use and learn OC. If you don't want to change, keep using Clover and booting legacy. Then your older El Capitan drive will still work as is with no BIOS changes.

I don't think I'll move to Big Sur until I do a new build, at which point I'll be happy to learn OpenCore and have the most compatible hardware for it to work as OOB as possible.

For the definition, do I just choose iMac 14,2 in Multibeast? It's been so long since my first install but I'm sure I chose MP 5,1 for it at that point. I expect I need to do some research on updating config.plist :/

Thanks for the HS info. I'll see if I can get that working first so at least I have a better fallback position and go from there... Encouraging that there's no major pitfalls to installing Catalina on this build though.

 

[trs96]

do I just choose iMac 14,2 in Multibeast?

If you use MB for HS then 14,2 is the default. Go with that if you don't plan on Big Sur later.

 

[reppie]

If you use MB for HS then 14,2 is the default. Go with that if you don't plan on Big Sur later.

How about for Catalina, once I've got a compatible GPU? Will the Catalina MB default to the right definition? I'm just worried at some point my Sandy Bridge CPU is going to be incompatible with the definition MB sets for the later OS

 

[trs96]

How about for Catalina, once I've got a compatible GPU? Will the Catalina MB default to the right definition? I'm just worried at some point my Sandy Bridge CPU is going to be incompatible with the definition MB sets for the later OS

Yes, the SMBIOS for Catalina is also 14,2 when you run Multibeast. Many people even use Sandy Bridge cpus for Big Sur without problems. They simply change to iMac 15,1 or 19,1 for Big Sur.

 

[reppie]

Much obliged Mr Moderator!