[Solved] Can I convert an old Mac Pro into a customac?

Is it possible to modify the hardware and EMI of my first generation Intel Mac Pro (macpro 1,1) so that it will run Sierra.

Back when it first became impossible for me to advance my early Mac Pro to graduate to Mountain Lion, I decided to stay with Snow Leopard (because Lion was getting a lot of bad press).

At that time, it was said that all my machine needed to run later MacOS operating systems was a more advanced graphics processor (easy to get, at least it was then) .... and an EMI upgrade (closely guarded by Apple then, but apparently possible, and legal/ethical ??? now with custom EMI having been developed by independent parties).

Is that still true? I understand that I might have to add some memory and that my 1+ GHz, two Xeon Dual processors might under-perform newer Macs running Sierra, but is it realistic to think that my old MacPro could still be a serviceable machine that runs Sierra?

Sierra demands a processor with SSE4.1 support.

No, it's not possible. You can upgrade to a Mac Pro 2,1 with a BIOS upgrade, but you have a dead end machine. See the MacRumor's Mac Pro forum section for more information > https://forums.macrumors.com/forums/mac-pro.1/.

However, you can gut the case and make a Hackintosh case mod. See https://www.tonymacx86.com/forums/mac-pro-mods.140/. I've made two, one from a PowerMac PPC case and another from a 2008 Mac Pro 3,1 case.

Thanks. I can see why dependence on an extended instruction set (SSE4.1) by later versions of the os would create a variety of difficulties that even replacing the CPU's wouldn't overcome. No need for further discussion here.