Does the 5.1 Mac Pro really utilise 1333mhz ram?

[LMR80]

One of the perks people mention of upgrading the firmware from 4.1 to 5.1 on a Mac Pro, is that it can utilise faster ram speeds.
I looked into this, and I'm a little confused..

According to Mactracker, the 4.1 and the 5.1 use the same memory apart from the E on the 2010.
Does this mean It will still run at 1066MHz and not 1333MHz when it's in my upgraded 4.1 to 5.1 machine?

Quote "240-pin PC3-10600E (1333 MHz) DDR3 ECC SDRAM (memory speed for certain configurations is 1066 MHz)"

Thanks

 

[DEMinSoCAL]

Not sure what you are asking. If you've "looked into this", you've surely seen people post proof that their RAM runs at 1333 if they use 1333 RAM. So, yes, if you upgrade the firmware in a 4.1 to 5.1 and use 1333 RAM, after following instructions your memory runs at 1333.

 

[DPUser]

So, yes, if you upgrade the firmware in a 4.1 to 5.1 and use 1333 RAM, after following instructions your memory runs at 1333...

...if your CPU supports 1333 RAM.

Fun Fact: A lot of RAM labeled 1066 is actually 1333. Happy surprise for many (including me) after upgrading firmware and CPU in a 4,1.

 

[frou]

PC3-xxxxxE vs PC3-xxxxxR is about "unregistered" vs "registered" RAM modules. That distinction is not about speed.

Basically all one needs to know about that distinction is that they can't be mixed, so all the modules in a cMP must be of one kind or the other.

IIRC the stock modules Apple shipped were E aka Unregistered aka UDIMMs.

 

[h9826790]

Yes, in the following screenshot, from the SMC version, you can tell this is a 4,1. From the Boot ROM Version, it's a 5,1. This is what the standard 4,1 flashed 5,1 looks like. With the correct CPU that support 1333MHz RAM (W3690 in this case), all 3x16G 1333MHz memory module recognise by the system and running at 1333MHz.

 

[LMR80]

Not sure what you are asking. If you've "looked into this", you've surely seen people post proof that their RAM runs at 1333 if they use 1333 RAM. So, yes, if you upgrade the firmware in a 4.1 to 5.1 and use 1333 RAM, after following instructions your memory runs at 1333.

Well yes, but from what I've seen its CPU dependent.
I should've worded my post and the title better; I just wasn't sure which processors worked with that speed, but it seems pretty obvious now.

Thanks
[doublepost=1467906936][/doublepost]

So, yes, if you upgrade the firmware in a 4.1 to 5.1 and use 1333 RAM, after following instructions your memory runs at 1333...

...if your CPU supports 1333 RAM.

Fun Fact: A lot of RAM labeled 1066 is actually 1333. Happy surprise for many (including me) after upgrading firmware and CPU in a 4,1.

Right I see, thanks for the info.

And interesting, I wasn't aware of that
[doublepost=1467906971][/doublepost]

PC3-xxxxxE vs PC3-xxxxxR is about "unregistered" vs "registered" RAM modules. That distinction is not about speed.

Basically all one needs to know about that distinction is that they can't be mixed, so all the modules in a cMP must be of one kind or the other.

IIRC the stock modules Apple shipped were E aka Unregistered aka UDIMMs.

Oh right, that makes more sense now.

Thanks
[doublepost=1467907026][/doublepost]

Yes, in the following screenshot, from the SMC version, you can tell this is a 4,1. From the Boot ROM Version, it's a 5,1. This is what the 4,1 flashed 5,1 looks like. With the correct CPU that support 1333MHz RAM (W3690 in this case), all 3x16G 1333MHz memory module recognise by the system and running at 1333MHz.

View attachment 639337

Right, understood.

Thanks for the post!

 

[ActionableMango]

The CPU guide linked in my signature lists the CPUs and which speed RAM they support.

 

[LMR80]

The CPU guide linked in my signature lists the CPUs and which speed RAM they support.

Excellent, thanks allot.