Parts recommendations for a Mojave/Snow Leopard build

[carrot]

Hi there

I'm wanting to put together a build that allows for both Snow Leopard and Mojave, as I need compatibility between PPC through Rosetta and 32-bit apps. I am also intending to run Windows 10 and Ubuntu.
I'm fed up with parts breaking on my 2011 MBP and am going down the DIY route to solve the issue once and for all.
The build is going to be used for graphics/3D/video work, and also for older software compatibility. It is not going to be daily-driven or be my main computer.
I am currently considering the following parts, after looking at the Snow Leopard build guide:

i7-2700k
32GB DDR3
Radeon HD 6870 2GB
ASUS P8Z68-V Pro/Gen 3
2x 240GB SATA SSD in RAID-0 for boot
1x 1TB SATA HDD
Blu-Ray writer
3.5 inch front panel memory card reader and USB 3.0
Corsair 550W PSU

I also have a few more questions and I hope that someone can please offer some feedback:

• The motherboard has firewire headers on it. If I connect an appropriate firewire bracket to the board will both SL and Mojave be able to use the port? Or will I require a Mac compatible PCIe firewire card instead? Having working FireWire on the computer is a must as I regularly import video from MiniDV camcorders through iMovie.
• In the DSDT library there is the ASUS P8Z66-V Pro, but not the Gen 3 version of the board. Will the existing DSDT work? Am I better off looking for the non-Gen 3 version to ensure compatibility?
• I understand Sandy Bridge was only supported starting with 10.6.8. As I have a retail disc, will I run into an issues between installing the retail disc and applying the combo update? Does iBoot solve the kernel support issues until 10.6.8 is running off the boot disk?
• Is Sandy Bridge supported by Mojave?

I'd be very appreciative for any guidance on this topic
Many thanks

 

[Edhawk]

While the HD 6870 is reported to work out of the box in OSX, it doesn't say that it is supported in Snow Leopard. I know the 2011 27" iMac came with a HD6790M card installed, so their is a good chance the HD6870 will work in Snow Leopard, but no certainty.

A HD5770/5870 or similar dGPU may be a better match with Snow Leopard. Might be easier to source too.

You may also find that any dGPU that works in Snow Leopard has been dropped from macOS, before you get to Mojave. Most if not all of these older dGPU's lack the features necessary for Apple's Metal graphics, which were a pre-requisite for a system running Mojave or newer. I think the HD7000 series support Apple's Metal features. But those cards only started being supported in Mountain Lion.

You may need to use two different graphics cards one for Snow Leopard and a newer one for Mojave that supports Metal.

Yes, you will have issues using a Retail DVD (10.6.3) with a Sandy Bridge CPU. Apple first released a Sandy Bridge iMac with a special build of 10.6.6. I don't recall iBoot solving the issue of using a Retail DVD with a Sandy Bridge CPU. However, someone else may know better.

You can run Mojave on a Sandy Bridge system but it is not natively supported. Some users here run Monterey on their Sandy Bridge systems, with some additional hacks. FYI, native support for the Sandy Bridge CPU stopped with High Sierra 10.13.6.

Building a Sandy Bridge system that runs Snow Leopard and High Sierra might be an easier option. As with your current plans you would need to use a different SMBIOS (Ivy Bridge or newer) when booting Mojave. Whereas the native Sandy Bridge SMBIOS would work with Snow Leopard up to and including High Sierra with no issues.