Other Samsung SM951 AHCI SSD bootable Mac Pro 5.1

[Schprecher]

Hi.

Guys, can someone confirm to Samsung SM951 AHCI SSD bootable for Mac Pro 4.1 or 5.1 under legacy boot.
this I need for install windows 7 on nvme and boot is in legacy.

or what nvme drive with AHCI can boot in legacy - for Mac Pro

thanks.

 

[joevt]

Legacy BIOS boot requires one of the 4 built-in SATA bays for MacPro3,1. Or DVD boot. I think OWC made some bootable PCIe cards (they contain a BIOS driver that's compatible with Boot Camp). An AHCI device probably won't have a BIOS driver.

I'm not sure if MacPro4,1 / MacPro5,1 improved legacy BIOS boot drivers much.

 

[Amethyst1]

An AHCI device probably won't have a BIOS driver.

I have a small collection of AHCI PCIe SSDs and can check which of them have an Option ROM.

 

[tsialex]

Hi.

Guys, can someone confirm to Samsung SM951 AHCI SSD bootable for Mac Pro 4.1 or 5.1 under legacy boot.
this I need for install windows 7 on nvme and boot is in legacy.

Maybe I'm missing something here, but Windows support for NVMe is only with UEFI installs.

Btw, NVMe is not supported by Windows 7 ISOs, requiring injection.

or what nvme drive with AHCI can boot in legacy - for Mac Pro

thanks.

NVMe and AHCI blades are not the same thing, the similarities stop with the M.2 M-key format/connector and being solid state, internality they work very differently.

Some ancient M.2 M-key NVMe blades had BIOS/Legacy support, like Samsung 950 PRO, but these blades only work with PCs and do not work with a MacPro5,1 at all, blocking POST when installed.

 

[joevt]

I have a small collection of AHCI PCIe SSDs and can check which of them have an Option ROM.

You can use my flashrom fork (requires my DirectHW, and pciutils forks) to grab the option ROMs of any PCI device on Intel macOS then use my DumpPCIRom.sh script to see if the option ROM has BIOS, OpenFirmware, or EFI images. I have to make some small changes to the code for PowerPC Mac OS X.

But like @tsialex says, even if it has a BIOS rom, it probably won't work with the BIOS compatibly layer of Mac EFI.

For Windows on old EFI Macs that use legacy BIOS to boot Windows, I would just use a SATA SSD that's connected to an internal drive bay.

 

[Schprecher]

thanks all guys for help.

one feature I can see with apple ssd based for iMac 2013 (nvme or ahci) SSUBX.
windows 7 recognize this ssd correctly under legacy, I can format or delete partition, but....

windows say I can't boot from this device because something not turned on in bios.

apple ssd native can recognize with stock firmware Mac Pro 5.1, I think this ssd is ahci based on sm951

in iMacs windows can boot from legacy on nvme native apple ssd, or modified on m.2 like intel 660 665p Ill checked it personally.

I think we have some route to boot in Mac Pro 5.1 , only on bay 1-4 , and this can was a ahci driver inside a bootrom

to find out this, in apple bios not descripted modules , or drivers.

we need professional for understand why iMacs can boot from any device, native apple ssds, or m.2 any! or sata device.