MP 1,1-5,1 OpenCore and MATT Card

[mode11]

Why would the MATT card need reflashing every 3 months? Presumably its flash will last a decade before showing any trouble (long after the the machine will have been retired from regular use)?

Or are the Mac Pro’s NVRAM routines somehow faulty / not fit for modern use, eventually resulting in a corrupt / bricked MATT card? Could the card be reflashed outside the Mac, if this should happen?

 

[tsialex]

Why would the MATT card need reflashing every 3 months? Presumably its flash will last a decade before showing any trouble (long after the the machine will have been retired from regular use)?

MATT card is SPI flash memory replacement, and is the exactly same design as the MacPro4,1 and MacPro5,1 have. The same limitations/issues a MacPro5,1 have with modern macOS usage will continue to have when the MATT card is installed.

Or are the Mac Pro’s NVRAM routines somehow faulty / not fit for modern use, eventually resulting in a corrupt / bricked MATT card?

It's not something that can be resumed easily as you wrote, but yes. I've written about this on the OpenCore and the BootROM threads, if you want to know all angles.

You'll also have problems when macOS updates are released since the payload to be added to the NVRAM is considerable. Some people are having problems with software updates since at least High Sierra and now with BigSur/Monterey changing to continuous software upgrades/rolling software upgrades, the issue is now mainstream.

Could the card be reflashed outside the Mac, if this should happen?

Yes. Uninstall it and re-flash the MATT card SPI flash memory with a ch341a and a SOIC/SOJ clip.

 

[mode11]

Having checked the price of the MATT card (about £55), I can understand your reservations. If they were £5-10 it would be a no-brainer.

I'm still unclear as to why even a fresh chip can become quickly corrupted when using a modern macOS though. Is the volume of writes so great these days that the 100,000 cycles will be consumed within a relatively short space of time? Surely we are still talking years rather than months? I checked the VSS store on my (2009) chip before I did a recent reflash, and it still had 40886 in the 'Full size' section, 6 months after a previous clean flash. So it doesn't appear to be getting hammered that hard.

It would be cool if a card were available that used a modern flash chip, plus a simple microcontroller that could translate the instructions for the original chip to it. But I guess it's a tiny market, and desoldering an 8-pin chip should the original die is not the end of the world.