1600Mhz DDR3 Ram in a Mac Pro 5,1?

[leoaf79]

Can you post the model number(s) of your DIMMs?

This is embarrassing… there is a heat sink installed on each module, and I’m not so sure about label truthfulness.

I’ll try to use dmidecode to get the real specs from the modules.

 

[flowrider]

^^^^You can get module specs from you Mac:

About This Mac>System Report>Memory

Lou

 

[tsialex]

I’d like to know if is possible to overclock the memory/processor bus in this case.

Not with a Mac Pro.

Btw, if the DIMM frequency was downgraded to 800MHz, it's probably a quad rank DIMM (4Rx4) made for IvyBridge v1 and v2 Xeons.

Nehalem and Westmere require 2Rx4 with a 36 chips limit.

 

[sheapuppy]

Not with a Mac Pro.

Btw, if the DIMM frequency was downgraded to 800MHz, it's probably a quad rank DIMM (4Rx4) made for IvyBridge v1 and v2 Xeons.

Nehalem and Westmere require 2Rx4 with a 36 chips limit.

Thanks for the info. I have a Mac Pro 5,1 2010 with a 2.8GHz Quad Core Xeon CPU. I have 4 sticks of Patriot Memory DDR3-8500. When I put 3 sticks, my speed is 1066 MHz. When I add the fourth stick, the speed drops to 800 MHz. I was totally stumped as to why this was happening.

 

[sheapuppy]

Can you post the model number(s) of your DIMMs?

I have a similar scenario with my cMP 5,1 2010 model. I'm using Patriot Memory 4x4GB PC3-8500 CL7 ECC with a 2.8GHz Quad-Core Intel Xeon CPU. With 3x4GB sticks (12GB), my cMP reads the memory at 1066 MHz, but with 4x4GB sticks (16GB), the memory downgrades to 800 MHz.