by Tom Nelson
The Mac Pro has long been the choice of both amateur and professional content creators and developers who expect performance and the ability to customize their workstations. Beginning with macOS Mojave, Apple started paring back support for some Mac Pro models, leaving many to wonder if it’s time to consider updating to a new workstation.
While there may be a bit of a thrill in updating to something new, the truth is, at least in this case, if you’re using a 2010 through 2012 Mac Pro, or the newer 2013 and later models of the Mac Pro, you may find that instead of updating, upgrading may be a better choice. With just a few changes, you can upgrade your Mac Pro and ensure it’s compatible with macOS Mojave; you can also increase its performance to meet your needs.
Mac Pro models from 2010 and later can all be upgraded to increase performance and ensure compatibility with macOS Mojave and later.
Memory Upgrades
The 2010 through 2012 versions of the Mac Pro were available in single and dual processor configurations that supported up to 12 processor cores. Each processor supported up to 4 DIMM (Dual-Inline Memory Modules) memory slots, resulting in the Mac Pro having either 4 or 8 memory slots that could be populated with DIMM modules.
The tricky bit about upgrading the 2010 through 2012 Mac Pros is that while there are 4 memory slots per processor, there are only 3 memory channels available to each processor. Memory channels are the means by which the processor or memory controller communicates with the RAM module. With a single processor Mac Pro, memory slots 1 and 2 each use a discrete memory channel, while slots 3 and 4 share the remaining memory channel. The same architecture is used for Mac Pros with dual processors; memory slots 1, 2, 5, and 6 are each connected to their own dedicated memory channel, while slots 3 and 4 share one of the remaining channels, and slots 7 and 8 share the final memory channel.
The way the memory channels are divided up has implications for how you add memory to your Mac Pro. To achieve the best available memory performance you should follow this sequence for installing RAM modules:
In a single processor Mac Pro:
- 2 DIMMs: Install in memory slots 1 and 2
- 3 DIMMs: Install in memory slots 1, 2, and 3
- 4 DIMMs: Install in memory slots 1, 2, 3, and 4
For best results, all DIMMS should be of the same size and speed; this is especially true when using both slots 3 and 4 since they share a memory channel. The slowest module will dictate the speed at which a memory channel operates. Placing a slow module in slot 4 will cause slot 3 to operate at the same speed.
Memory module for use in 2010 through 2012 Mac Pro models.
In a dual processor Mac Pro:
- 2 DIMMs: Install in memory slots 1 and 2
- 3 DIMMs: Install in memory slots 1, 2, and 3
- 4 DIMMs: Install in memory slots 1, 2, 5, and 6
- 6 DIMMs: Install in memory slots 1, 2, 3, and 5, 6, 7
- 8 DIMMs: Install in memory slots 1, 2, 3, 4, and 5, 6, 7, 8
Once again, it’s best to use the same size DIMMs in all channels, and especially important to make sure DIMMS in slots 3, 4, and 7, 8 use the same size and speed.
OWC offers memory for the 2010 through 2012 Mac Pro in 2 GB, 4 GB, 8 GB, and 16 GB sizes, allowing you to install up to 64 GB in a single processor Mac Pro and 128 GB in a dual processor model.
The 2013 cylindrical Mac Pro has a total of four memory slots, two on each side. Apple recommends that memory slots be populated with identical DIMMs in the following configurations:
- 12 GB: 4 GB DIMMs in slots 1, 2, and 3
- 16 GB: 4 GB DIMMs in slots 1, 2, 3, and 4
- 32 GB: 8 GB DIMMs in slots 1, 2, 3, and 4
- 64 GB: 16 GB DIMMs in slots 1, 2, 3, and 4
While the configurations suggested by Apple will provide the best overall memory performance, you’re not limited to these configurations. As an example, you could create a 20 GB system by adding an 8 GB DIMM in the open fourth slot in the standard 12 GB configuration. Or, you could create a 24 GB configuration by removing the 4 GB DIMM in slot 3 of the 12 GB system, and adding two 8 GB DIMMS in the two open slots.
The only real restriction for the 2013 Mac Pro is that UDIMMs (Unregistered Dual Inline Memory Modules) can’t be mixed with RDIMMs (Registered Dual Inline Memory Modules). Generally, the smaller size DIMMS will be of the unregistered variety, while larger ones with be the registered type.
OWC offers memory upgrades for the 2013 Mac Prousing 4 GB UDIMMs, and 8 GB, 16 GB, and 32 GB RDIMMs.
