Mac Pro 4,1 install 1333 ECC RAM

[trchern]

Without upgrading firmware to 5,1, can I install 1333 DDR3 RAM instead of 1066 RAM on a Mac Pro 4,1 machine?

Because I wanted to upgrade to 5,1 eventually, but currently I need a higher RAM. So I think it would be reasonable to buy 1333 instead of 1066.

Thank you,

 

[ActionableMango]

Yes. The 1333 RAM will run at 1066 until you upgrade the firmware and get an appropriate CPU.

 

[Mac Hammer Fan]

My RAM in both Macs went from 1066 to 1333, not after the 5,1 firmware update but after installing in addition a Hex Core 3,33 GHz and zapping the PRAM. ActionableMango is right but you need to reset the PRAM (NVRAM) too.
Reboot with option + command + p + r.

 

[MarkC426]

Slightly off topic, but not....
Is the pram reset doable without an efi gpu?
Just planning ahead.

 

[Dr. Stealth]

Slightly off topic, but not....
Is the pram reset doable without an efi gpu?
Just planning ahead.

Yes... No Problem....

 

[ActionableMango]

Slightly off topic, but not....
Is the pram reset doable without an efi gpu?
Just planning ahead.

If that non-efi gpu you have is using Nvidia drivers, keep in mind that an nvram reset is also going to clear the "use Nvidia web drivers" boot parameter.

 

[MarkC426]

Thanks, its an RX580 pulse

 

[h9826790]

My RAM in both Macs went from 1066 to 1333, not after the 5,1 firmware update but after installing in addition a Hex Core 3,33 GHz and zapping the PRAM. ActionableMango is right but you need to reset the PRAM (NVRAM) too.
Reboot with option + command + p + r.

PRAM reset is not a requirement but more like a fix. Only do that if the RAM cannot negotiate at the “correct” speed. e.g. I never need to do that on my cMP. The RAM automatically run at 1333MHz after the hardware upgrade completed.

 

[Mac Hammer Fan]

PRAM reset is not a requirement but more like a fix. Only do that if the RAM cannot negotiate at the “correct” speed. e.g. I never need to do that on my cMP. The RAM automatically run at 1333MHz after the hardware upgrade completed.

I had to ZAP the PRAM to get the 1333 speed, honestly.

 

[h9826790]

I had to ZAP the PRAM to get the 1333 speed, honestly.

I trust you. I just mean that’s not a mandatory procedure, but only required if the speed doesn’t change automatically.