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Two green DDR3 DIMMs with gold contacts and silver heat spreaders

OWC

OWC 16GB DDR3 1333MHz ECC Registered 2x8GB Memory Upgrade OWC1333D3X8M16K

SKU CH-CF83-HK91G MPN OWC1333D3X8M16K

16 GB DDR3 1333 MHz ECC registered kit for 2009–2012 Mac Pro Xeon systems

  • Capacity16GB (2 x 8GB)
  • SpeedDDR3 1333 (PC3 10600)
  • CAS LatencyCL9
  • ECCYes
  • Buffered/RegisteredRegistered

Capacity 16GB (2 x 8GB)

  • 16GB matched kit doubles memory capacity for Mac Pro towers
  • DDR3 1333MHz ECC registered DIMMs ensure data integrity under load
  • CL9 latency at 1.5V keeps response tight for Xeon workflows
  • Validated for 2009-2012 Mac Pro 4,1 and 5,1 models up to 48GB
  • Cannot mix with unbuffered modules or system will not boot

Mac Pro DDR3 ECC Registered Kit

This 16GB kit contains two matched 8GB DDR3 1333MHz ECC Registered DIMMs built for 2009 to 2012 Mac Pro models. It targets owners of MacPro4,1 and MacPro5,1 systems who need registered memory to reach higher capacities. The modules operate at 1.5V with CL9 latency and are not compatible with standard desktop PCs.

Capacity headroom and mixing limits

The paired 8GB sticks provide 16GB total and support configurations up to 48GB in the 2010 quad-core Mac Pro when all slots are filled with registered modules. Registered and unbuffered ECC memory cannot be mixed; installing this kit alongside existing unbuffered DIMMs will prevent the system from booting. Backwards compatibility covers 1066MHz PC3-8500 Mac Pro models.

Upgrade path from unbuffered or smaller kits

This kit replaces unbuffered memory when a registered configuration is required for capacities above the unbuffered limit. The jump is worth it when moving from smaller matched pairs or when populating all slots in a 12-core or 8-core 2010 to 2012 Mac Pro. It is not for buyers who need unbuffered modules or who plan to mix memory types.

Highlights

  • 16GB matched kit doubles memory capacity for Mac Pro towers
  • DDR3 1333MHz ECC registered DIMMs ensure data integrity under load
  • CL9 latency at 1.5V keeps response tight for Xeon workflows
  • Validated for 2009-2012 Mac Pro 4,1 and 5,1 models up to 48GB
  • Cannot mix with unbuffered modules or system will not boot

Specifications

Capacity16GB (2 x 8GB)
SpeedDDR3 1333 (PC3 10600)
CAS LatencyCL9
ECCYes
Buffered/RegisteredRegistered

Other versions of this model

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Questions about this item

Will these registered ECC modules work alongside the unbuffered ECC memory already installed in my Mac Pro?

No, the Mac Pro cannot mix registered and unbuffered ECC memory; you must remove any existing unbuffered modules before installing this kit or the system will not boot.

How can I verify the kit is running at the correct 1333 MHz speed and CL9 latency after installation?

Open System Information on the Mac Pro and check the Memory section; each DIMM should show 1333 MHz, PC3-10600, ECC Registered and CAS latency 9.

Does the box contain only the two 8 GB DIMMs or are any tools or additional cables included?

The package includes the matched pair of 8 GB 240-pin DDR3 registered ECC DIMMs; no tools, cables or other accessories are supplied.

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