Sometimes 16 or 32 GiB memory just won’t serve.
Shown below is a very busy iMac 5K, chewing up all the CPU cores:
- 28.3 GiB memory in use
- 35.6 GiB memory used for file system caching
- 5 GiB wired (locked down) memory
- Outstanding: no swap (disk I/O) is being used because of a memory shortage (good!).
- Compressed memory is only 2.1MB (effectively zero, in context).
Things would slow to a crawl trying to do this on a system with 16GB, and performance would be substantially impaired on a system with 32GB: only 64GB will do for this kind of usage.
* For the first time ever I (Lloyd) bought and am actively using an iMac 5K. In many respects it is superior to the fastest 2013 Mac Pro (3.3 GHz 8-core). Its main weakness is a single Thunderbolt bus with only two ports, a real headache for multiple displays and networking and storage all together (daisy chaining and one bus have real practical limits). So I use it as a compute station for multi-minute Photoshop jobs using wonderfully fast Thunderbolt networking to connect to the Mac Pro.
While 64GB is a smart move for a “set and forget” system for the high-end configuration, many users do not need a full 64GB. So add to the memory already paid for that came with the iMac: Apple configures an 8GB iMac 5K as 2 X 4GB and a 16GB iMac 5K as 2 X 8GB, thus leaving two memory slots open. When a full 64GB is not needed, keep the two modules already there, but add 2 X 8GB or 2 X 16GB as follows:
The iMac 5K uses dual channel memory, so this 2 module + 2 module approach poses no performance issue.
See also on the new iMac 5K:
- Best Choice for Color Gamut and Real Calibration is a Professional Solution
- $150 off the Brand-New Apple iMac 5K
- MPG’s Computer and Storage Wish List at B&H Photo
- The Apple iMac 5K ('Late 2015')
- Apple’s DCI(P3) Color Gamut Improves Upon Longstanding Marginal Gamut, Yet Makes Little Sense in Context for Amateurs or Pros
- New Apple iMac 5K 27" Supports 64GB Memory, OWC Has Kits Available
- New Apple iMacs Available for Pre-Order at B&H Photo + BUYING RECOMMENDATIONS