See my recommended Mac for photographers and similar higher users.
Contact Lloyd for advice on system selection and configuration, backup and fault tolerance etc.
See Apple 2019 iMac 5K: Two hits with a Big Miss and 2019 iMac 5K.
Brian B writes
Your content on the 5K iMac changes has been good. Especially the information on Thunderbolt 3 single-bus concerns, I would never have considered it otherwise. I don't think the TB3 bandwidth will be a problem for me.
When looking at your recommended Apple 2019 iMac 5K for easy-to-use configurations, I was surprised that the iMac only had a 580x.
Is That is why you recommend 580x over Vega 48, especially considering your post on LR / PS, without using eGPU? Isn't it just a good value?
MPG: The GPU upgrade to the Radeon Pro Vega 48 is $ 450. For perspective, it's about the cost of upgrading to the 8-core CPU (highly recommended), or a 64GB memory upgrade or going to a 1
Therefore, my recommendation is not a recommendation against Radeon Pro Vega 48 GPU Upgrade, but rather a statement such as unless the budget is unlimited go first for 8 – core CPU, SSD (2TB, 1TB minimum) and memory (64GB or more)).
Continuing under …
Considering a maximum output in the 2019 iMac 5K, it's best to take a break and find out if an iMac Pro would be a better choice for your workflow. I offer advice for such decisions .
Please purchase your Macs through B&H Photo via the links on this page . B&H Photo provides the test units to MPG.
Previously, similar GPU upgrades had no noticeable gains in performance for what I do  and was generally around 20%, which could be shown on reference targets, but in the context of real work, was not meaningful. For example, would you pay $ 450 to take the time from 5 seconds to 4 seconds for an operation done 10 times a day?
Claim for speed improvements should be discounted heavily unless there is continuous use of the GPU. Nevertheless, if not nearly everything I do as a photographer in Photoshop, the GPU uses only a fraction of the time of the total operation in short cases. Although operations like Adobe Camera Raw Enhance Details (GPU Intensive) are increased by 25%, not 100 seconds saves a day (rarely) does not impress. By far, I wanted to have 128 GB of memory; My budget is not open.