MP 1,1-5,1 About why it can’t be upgraded to 1333 MHz RAM

[ddhhddhh2]

I have a question let me confuse as long time. My current RAM is Kingston 8GB DDR3 1600 1.5v (KVR16N11/8) x 4, my firmware is 140.0.0.0.0, MacPro 5,1 (2010) Single CPU X5690, a few years ago, When upgrading the firmware, NVRAM was also cleared.

Since I have a chance to upgrade to a dual CPU tray these days, I am choosing a suitable RAM. This time I plan to use 16G ECC RAM. However, I remembered this matter. Is there something wrong with my current RAM and MacPro settings? ? Otherwise why does it run at 1066 MHz?

The current system is macOS Catalina, using the opencore solution. However, before I used opencore (macOS 10.12~13), the memory was still running at 1066MHz, so I never understood. What was wrong?

Thanks for the help

 

[tsialex]

https://www.kingston.com/datasheets/kvr16n11_8.pdf

This is a low cost standard desktop RAM, a non-ECC UDIMM with 2Rx8 ranking stated on the data sheet, you need ECC UDIMM or ECC RDIMM with the 2Rx4 rank or the memory controller RAM frequency will be downgraded.

Mac Pro is a workstation/SMBS server platform, not a desktop one, you have to play with different rules than desktop computers and using the a different type of memory than what is required has penalties or don't even work.

 

[ddhhddhh2]

https://www.kingston.com/datasheets/kvr16n11_8.pdf

This is a low cost standard desktop RAM, a non-ECC UDIMM with 2Rx8 ranking stated on the data sheet, you need ECC UDIMM or ECC RDIMM with the 2Rx4 rank or the memory controller RAM frequency will be downgraded.

Mac Pro is a workstation/SMBS server platform, not a desktop one, you have to play with different rules than desktop computers and using the a different type of memory than what is required has penalties or don't even work.

Really? I thought the 2010 MacPro was encouraged to use desktop memory, after you told me about 2Rx4, I watched Kingston 8GB DDR3 1600 1.5v (KVR16N11/8), but I couldn’t find any indication of 2Rx? on it. It looks like it is, thank you.

 

[Nguyen Duc Hieu]

For ECC RAM, the system will automatically lower the operation frequency to ensure system stability.
This is clearly stated in any workstation manual (HP, Dell, Lenovo) of the same era as Mac Pro.
No surprise at all to see the same principle is applied on the Mac Pro.

 

[tsialex]

For ECC RAM, the system will automatically lower the operation frequency to ensure system stability.
This is clearly stated in any workstation manual (HP, Dell, Lenovo) of the same era as Mac Pro.
No surprise at all to see the same principle is applied on the Mac Pro.

Please explain me what this have to do with the OP question?

His memory is a low cost desktop unregistered non-ECC DIMM, besides that is a PCB with a ranking that is not compatible with Nehalem/Westmere Xeons. You can see the details on the data sheet that I've linked.

Btw, it's not exactly the way you wrote, ECC RAM that meets the requirement of the platform, will work at the correct frequency.

For a MacPro5,1 the correct memory is ECC UDIMM or ECC RDIMM 1333MHz with a 2Rx4 ranking (up to 36 memory chips or 36 memory chips plus the register controller).

ECC width = 72 bits
2R = dual rank, two CS lines
x4 = chip width in bits

So, 72 bits wide / 4 bits wide per chip * 2 ranks = 36 chips per DIMM*.

*Some DIMMs are engineered to use less memory chips, but it's always a multiple of 9 chips.

 

[Nguyen Duc Hieu]

Please explain me what this have to do with the OP question?

His memory is a low cost desktop unregistered non-ECC DIMM, besides that is a PCB with a ranking that is not compatible with Nehalem/Westmere Xeons. You can see the details on the data sheet that I've linked.

Btw, it's not exactly the way you wrote, ECC RAM that meets the requirement of the platform, will work at the correct frequency.

For a MacPro5,1 the correct memory is ECC UDIMM or ECC RDIMM 1333MHz with a 2Rx4 ranking (up to 36 memory chips or 36 memory chips plus the register controller).

ECC width = 72 bits
2R = dual rank, two lines can be accessed simultaneously
x4 = chip width in bits

So, 72 bits wide / 4 bits wide per chip * 2 ranks = 36 chips per DIMM*.

Some DIMMs use less memory chips, but it's always a multiple of 9 chips.

Sorry, maybe my post is not relevant to OP question.
But in the manual of HP workstation Z400, Z800, it's clearly stated that: If all of the RAM slots are populated, the machine will lower RAM frequency. i.e. 1333MHZ RAM will operate at 1066MHz only.

 

[Jedispirits]

Really? I thought the 2010 MacPro was encouraged to use desktop memory, after you told me about 2Rx4, I watched Kingston 8GB DDR3 1600 1.5v (KVR16N11/8), but I couldn’t find any indication of 2Rx? on it. It looks like it is, thank you.

Tsialex explained you perfectly what you need.

I only want to add (for my very bad experience) that you should avoid buying cheap memory modules from places like Aliexpress. Even if they are suposed to meet the specs, all I bought there only runned at 1066.

I finnaly bought old HP Servers memory modules on eBay, and they worked perfectly at 1333

Regards,

Llorenç

 

[ddhhddhh2]

Tsialex explained you perfectly what you need.

I only want to add (for my very bad experience) that you should avoid buying cheap memory modules from places like Aliexpress. Even if they are suposed to meet the specs, all I bought there only runned at 1066.

I finnaly bought old HP Servers memory modules on eBay, and they worked perfectly at 1333

Regards,

Llorenç

I am grateful for you to share your experience. I really don’t know anything. I didn’t expect that after so many years, I still have a new experience with this machine. I will receive the upgraded parts in about a week. These sharing are very useful to me. It was helpful, thank you all.