MP 1,1-5,1 Need help with Mac Pro 1,1 - GPU and installing El Capitan

[shermandy]

I am working on a family member's Mac Pro 1,1 that they bought on eBay for cheap.

It wasn't booting at all. I struggled to get the machine to see my patched El Capitan USB stick. However, after about a million random attempts, it booted to the USB when I held down the C key (why, I don't know but it worked).

I installed the OS on the old HDD that came with the machine. It seems to work as expected.

However, the family member now wants to upgrade to a 1TB Samsung SSD. The Mac Pro 1,1 recognized the drive but I can't boot to the USB again. Whenever I hold down Option on boot, the machine never loads. The flash drive's LED flickers repeatedly but the machine will never load anything.

Adding to the problem is my lack of a boot screen. The machine as a GT120 installed but it must not be the version with the correct boot EFI files. I don't see anything on screen until it gets to the login screen. So, I have no idea what's happening when I hold down the Option key (or any key, for that matter).

I've also tried selected the USB from the Control Panel "Start Up Disk" option but it doesn't appear as an option - only the El Capitan install on the old HDD appears as an option.

Can you wonderful, kind, beautiful people recommend the steps I should take? I don't know if I should focus first on installing the OS to the SSD or if I should worry about the missing boot screens. Should I replaced the GPU? If so, I have NO idea what to get. The advice on the Internet is horribly confusing. Should I make a new install USB?

TLDR: can't install El Capitan on my Mac Pro 1,1's new Samsung SSD. I suspect it's because I can't see any boot screens until the login prompt. How do I proceed?

 

[hwojtek]

You install on a different, El Capitan-compatible Mac, swap both boot.efis and kernel, install the SSD into MP. Or just have a read of one of our handy "How to install El Capitan on an unsupported Mac" threads:
https://forums.macrumors.com/threads/os-x-el-capitan-on-unsupported-macs.1889851/
https://forums.macrumors.com/threads/2006-2007-mac-pro-1-1-2-1-and-os-x-el-capitan.1890435/

 

[shermandy]

Thank you for the links! I will work on those steps this evening and will report back. I have a Fall 2013 MacBook pro that is on the most recent os (Mojave?) - Can you confirm if I can complete the necessary steps with that machine?

Also, can you recommend a GPU that I can use to get boot screens on the Mac Pro 1,1? I don't want to flash any new firmware or modify it physically. I'd like something that I can buy cheaply and install without hassle (if possible).

 

[Macschrauber]

Get an Apple HD5770, this with two mini display ports and dvi. Get the pcie power cable as well.

Gt120 is for 64 bit efi mac pro 3.1 to 5.1, sell it.

For El Cap simply copy your drive with carbon copy cloner to the ssd. Format the ssd with guid and hfsplus journaled.

 

[shermandy]

Get an Apple HD5770, this with two mini display ports and dvi. Get the pcie power cable as well.

Gt120 is for 64 bit efi mac pro 3.1 to 5.1, sell it.

For El Cap simply copy your drive with carbon copy cloner to the ssd. Format the ssd with guid and hfsplus journaled.

Thank you!

Can you confirm that this GPU would provide boot up screens on the Mac Pro 1,1?

Also, would there be any performance loss if I clone the drive to the SSD?

 

[Macschrauber]

1. this is the 5770 I wrote about
2. no, btw enable trim by entering in Terminal

sudo trimforce enable