MP 1,1-5,1 MP 4,1 flashed to 5,1 upgrade options and pitfalls to avoid ?

[antoine23]

Hi, I'm looking for advice on a few topics (bootrom, bootscreen, nvram bricking, pcie SSD), I think I'm confusing stuff and would appreciate help.

I have a MP4,1 flashed to 5,1 on El Capitan with a GTX680 Windows (not flashed). It is connected to a 4K screen via DP.
I don't have boot screen right now.

1) Does it makes sense to update to latest bootrom ? I've read (but maybe misunderstood) that there are issues with NVRAM that can brick the machine and require soldering.

I read this: https://forums.macrumors.com/threads/macpro5-1-bootrom-thread-144-0-0-0-0.2132317/ and the first post talks about multiple things:
a) MP4,1 / MP5,1 cross flashing that become bricked over time ?? For a while 4,1=>5,1 was recommended, it is no longer the case ?
b) how to dump the ROM, should I do it before anything as a backup ??
Later comments also seem to state that you need to reflash the ROM several times a year

Where could I find summed up information on that topic?

2) I would like to add a MBP SSD on a PCIe Adapter, but I've read they appear as external drives. Would a boot rom update fix this, even on El Capitan ?

3) I've also read about OpenCore to install more recent macOS versions, would they be affected by the NVRAM bricking issue ?

4) Would updating to OpenCore enable boot screen on 4K over DP with a non flashed card ?

Thanks!

 

[Borowski]

For bootrom dumping and flashing, you can use:

ROMTool from dosdude1, unzipping password is "rom": https://dosdude1.com/apps/ROMTool.zip

Or the tool from member Macschrauber: https://forums.macrumors.com/thread...es.2333460/page-4?post=32055801#post-32055801

Does also automatic analyzing your bootrom or flashfile and warns if it found corruption.

It is not too bad to have a few copies of the bootrom.

 

[Macschrauber]

2) no
3) yes, the nvram gets more used by OpenCore and the modern OS. An installation of, say Monterey, are various boots. Each boot fills the nvram with various extra variables.

Better start such an installation with plenty of free nvram space.

nvram gets filled and emptied in a circular progress. To check how much space is available you can use the Dumper.

4) Depends, 4k is picky on old GPUs. Check the DVI output on a standard display (mode) if 4k is not working.

Also you can read about flashing the GTX680 for bootscreen. Maybe upgrade the GPU as OS newer Big Sur have no native Kepler drivers no more.

GPUs with a valid GOP part in their firmware can get a bootscreen, even without OpenCore by adding a module to the Mac Pro firmware. Read about EnableGop.