All Posts by Date or last 15, 30, 90 or 180 days.
also by Lloyd: photography and
Thank you for purchasing through links and ads on this site.
diglloyd B&H Deal Finder...
Buy other stuff at
Today’s Deal Zone Items... Handpicked deals...
$4499 $3499
SAVE $1000

$249 $219
SAVE $30

$1398 $898
SAVE $500

$1699 $1349
SAVE $350

$21999 $19999
SAVE $2000

$8399 $7599
SAVE $800

$1149 $799
SAVE $350

$260 $180
SAVE $80

$4998 $3998
SAVE $1000

$569 $519
SAVE $50

$899 $799
SAVE $100

$2347 $1997
SAVE $350

$883 $633
SAVE $250

$1299 $949
SAVE $350

$1699 $1349
SAVE $350

$2798 $2498
SAVE $300

$1199 $1099
SAVE $100

Upgrade the memory of your 2020 iMac up to 128GB
Organic Lab Tested Full Spectrum CBD

20% off every day with coupon code diglloyd20 at

Updated formula with more CBD!
100% organic non-GMO, no additives or preservatives, lab tested for purity and quality.

Reader Question: Radeon Pro Vega 48 GPU Upgrade for 2019 iMac 5K

See my recommended Macs for photographers and similar higher-end users.

Contact Lloyd for consulting on choosing and configuring a system, backup and fault tolerance, etc.

See Apple 2019 iMac 5K: Two Hits with One Big Miss and 2019 iMac 5K.

Brian B writes

Your content on the 5K iMac changes has been great. Especially the information on the Thunderbolt 3 single-bus concerns, I would never have considered it otherwise. I do not believe the TB3 bandwidth will be an issue for me.

When looking at your Recommended Apple 2019 iMac 5K for high-end users config, I was surprised to see that the iMac only had a 580x.

Is there a reason why you recommend the 580x over the Vega 48, especially considering your post on LR/PS not utilizing eGPU? Is it just not a good value?

MPG: the GPU upgrade to the Radeon Pro Vega 48 is $450. For perspective, that’s about the cost of upgrading to the 8-core CPU (strongly recommended), or a 64GB memory upgrade or going to a 1TB SSD from the performance-killing and noise-making Fusion drive. ALL of those upgrades should come before the GPU upgrade, but if the budget is wide-open, then add the top-end GPU also.

Thus my recommendation is not a recommendation against the Radeon Pro Vega 48 GPU Upgrade, but rather a statement that unless the budget is unlimited, go first for the 8-core CPU, SSD (2TB, 1TB minimum), and memory (64GB or more).

Continues below...

Considering a maxed-out 2019 iMac 5K, it is best to pause and take stock of whether an iMac Pro would be a better choice for your workflow. I offer consulting for such decisions.

Please buy your Macs through B&H Photo via the links on this site. B&H Photo provides the test units to MPG.

Recommended Apple 2019 iMac 5K for high-end users
BUT buy with 8GB then upgrade the memory to 128GB

In the past, similar GPU upgrades have had no perceptible gains in performance for what I do and were generally around 20%, which could be shown on benchmarks but in the context of real work, were not meaningful. Would you, for example, pay $450 to take the time from 5 seconds to 4 seconds for an operation done 10 times a day?

Claims of speed improvements should be discounted heavily unless there is continuous GPU usage. Yet much if not nearly all of what I do as a photographer in Photoshop uses the GPU in brief bursts lasting only a fraction of the time of the total operation. Even if operations like Adobe Camera Raw Enhance Details (GPU intensive) are sped up by 25%, saving even 100 seconds a day (infrequently) does not impress. I’d far, far rather have 128GB memory; my budget is not wide open.The Adobe Camera Raw Enhance Details feature is now a core part of my image processing pipeline—always a win, never a loss seen yet.

My photography workflow

CPU Usage for over a minute using
Adobe Camera Raw Enhance Details

What I am wondering and without a good answer yet is just how much a faster GPU can benefit things. Shown below, CPU usage is sporadic and not very high for all 8

See the discussion of GPU speed and the Adobe Camera Raw Enhance Details feature over at in Adobe Camera Raw Enhance Details Feature: Integrated into my Workflow... How Much Does it Use the GPU?.


CLICK TO VIEW: Recommended 2019 Apple iMac Variants for Photographers

CLICK TO VIEW: Memory for iMac 5K
View all handpicked deals...

Pentax 8x42 S-Series SD WP Binoculars
$249 $219
SAVE $30 | Terms of Use | PRIVACY POLICY
Contact | About Lloyd Chambers | Consulting | Photo Tours
Mailing Lists | RSS Feeds | Twitter
Copyright © 2020 diglloyd Inc, all rights reserved.
Display info: __RETINA_INFO_STATUS__