See my recommended Macs for photographers and similar higher-end users.
Today’s announcement of the 2019 iMac 5K is welcome indeed, but bittersweet for one key feature reason, and one personal reason.
The 2019 iMac 5K is essentially a CPU and GPU upgrade which are terrific upgrades and very welcome if one is buying fresh—the CPU should be a huge upgrade for Photohop and Lightroom users and similar.
- Improvement: faster CPU options, with 6 or 8 cores
- Improvement: faster GPU option.
- Improvement: up to 128GB memory.
- Unchanged: user installable memory, 4 slots (not soldered on).
- Unchanged: same display.
- Handicap or feature: lacks the T2 chip which avoids some problems, but also lacks hardware encrption.
- Handicap: lacks 10 gigabit ethernet.
- Handicap: single Thunderbolt 3 bus with only two ports.
- Handicap: requires macOS Mojave
MPG recommends buying the 8GB memory configuration of the 2019 iMac 5K, and upgrading the memory with 64GB of OWC memory, for a savings of about $550 (as this was written). Basically, you can get 64GB for less than 32GB from Apple.
2019 iMac 5K: still a single Thunderbolt 3 bus
From the Apple sales page: “Connectivity It’s very well-connected” = huh? The 2019 iMac 5K has the poorest set of ports of any Mac desktop. Apple does not mention that if you add an external 5K display, more than half the Thunderbolt 3 bandwidth is consumed.
Here’s the rub for me and other high-end users: a key problem and headache for me with the 2017 iMac 5K has been the single Thunderbolt 3 bus with only two ports, crippling my ability to use my Thunderbolt 3 devices simultaneously and throttling peak performance, and making a 2nd 5K display highly undesirable due to it gobbling up most of the bandwidth.
The 2019 iMac 5K retains a single Thunderbolt 3 bus with only two ports. If this is the means of differentiating the 2019 iMac 5K from the iMac Pro, then it’s a sad story for customers hoping for a less expensive version of the iMac Pro.
The personal reason, presumably relevant only to buyers in a similar situation, is that in essence I’d have to spend $5230 to get a faster CPU and GPU—that’s it—the display is the same, the SSD would be the same, the 64GB memory would be the same. While I’d love the upgrade, I don’t have that kind of money.
If cost is not a concern, the $450 upcharge for the Radeon Pro Vega 48 is worth having. However, actual performance gains in the past for such upgrades has been unpersuasive, so unless the budget is wide open, first go with the fastest CPU, minimum 2TB SSD and 64GB or 128GB memory. Also, once into a maxed-out 2019 iMac 5K, it is best to pause and take stock of whether an iMac Pro would be a better choice. I offer consulting for such decisions.
The iMac Pro has two Thunderbolt 3 busses, but that costs another $1200, and my bet is that the 8-core 2019 iMac 5K will outperform the 8-core iMac Pro for most all tasks most photographers do. Thus the iMac Pro is also a flawed choice—and both come at a very high price.