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OWC Accelsior 1A Apple Factory SSD to PCIe Adapter Card
OWC Accelsior 1A Apple Factory SSD to PCIe Adapter Card
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Memory 256GB Kit (4x64GB) 2666MHZ DDR4 LRDIMM PC4-21300  1,576.17EUR 
Ex VAT of 21% 


256.0GB OWC Memory Upgrade Kit

Memory Image
Product Specs:
  • Technology: DDR4 LRDIMM 288 Pin
  • Density: 4 x 64GB (65536MB)
  • RoHS: Yes
  • Pin Count: 288-pin
  • Op. Temp.: 0C to +85C
  • Data Rate: DDR4-2666 V-R
  • Speed: PC4-21300
  • CL: 17
  • Voltage: 1.2V
  • ECC: Yes
  • Module Ranks: (2H TSV 4G) x 36
  • Low Noise 8-Layer PCB
  • Meets and/or Exceeds Apple/Intel Specifications
  • Fully Compliant with JEDEC specifications
  • RoHS Certified
  • Free Installation Videos & Manuals
  • Warranty Safe Upgrade.
  • OWC Memory Lifetime Limited Warranty including the OWC Lifetime Advanced Replacement Program
  • Why do I need more RAM?
iMac Pro can use either RDIMM or LRDIMM, but they cannot be combined. Additionally, LRDIMM modules must all be of the same size. 

macOS 10.14.3 Mojave or later must be installed before installing any kits utilizing 64GB or 128GB memory modules.
Professional Installation Required!
The iMac Pro DOES NOT feature a memory door on the back allowing for easy upgrades. Upgrading the iMac Pro's memory requires dismantling the computer to gain access to the memory slots. This is a highly complex process that requires a skilled technician.
This memory kit and included memory is for Apple iMac Pro Models only. Memory provided in this kit is special config for the iMac Pro ONLY and is NOT compatible with Apple iMac Models. Included memory also compatible with PC desktops or servers which use DDR4 2400 registered modules.


This OWC Memory is compatible with... Learn how to find your Mac's model ID or PC specs
iMac Intel
iMac Pro
(27-inch Late 2017)
(December 2017) 
Model ID: iMacPro1,1
3.2GHz 8-core, 3.0GHz 10-core, 2.3GHz 14-core, 2.5GHz 18-core
Install Videos coming soon




  • (2) 64GB 2400MHZ DDR4 RDIMM PC4-19200
  • (1) 27" iMac Adhesive tape set for proper display resealing




Lifetime Replacement Warranty

This product was added to our catalog on 21/08/2020.
First Product Previous Product 4 of 4 in iMac Pro 27" 2017