The most important things you can do to improve performance of LrC and Ps:

1) Replace the startup drive with an SSD. This is difficult on an iMac, but doable if you use a kit from OWC. If you decide to crack open the case and do that, watch their videos and then read the Dozuki guides at iFixIt.com for your model. Then follow along with the video, using a smartphone or another computer. And if you do this, put the largest SSD you can afford into it!

Personally, I'd just get an M1 iMac (midrange with 16GB RAM and 1TB SSD). Sell the 2017 while it's still worth a little.

2) If you're going to keep the 2017 iMac, up the RAM to at least 16GB. Intel processors need as much RAM as you can give them.

3) Consider using Thunderbolt SSDs for all external storage used for imaging.

THE MOST important things you can do to speed up performance of these Adobe apps is to improve I/O speed. An SSD is the most effective tool for this. SSDs are an order of magnitude faster than hard drives with spinning platters. For example:

I recently bought an M1 MacBook Air. I used Black Magic Disk Speed Test to clock the performance of my drives. Here are sample results:

Internal 1TB SSD: Write: 3265 MBPS Read: 2982 MBPS

External 2TB Samsung T7 (USB 3.2 connection): Write: 665 MBPS Read: 691 MBPS

External 3TB OWC MercuryElitePro 7200 RPM conventional drive: Write: 32.3 MBPS Read: 30.3 MBPS

The math boils down to this:

My external conventional hard drive is only ONE PERCENT the speed of my computer's internal SSD!

My Samsung T7 USB-C drive is only 20%/23% the speed of my computer's internal drive.

The next most important addition on Intel machines is adding RAM, because it reduces the need for swapping data in and out of memory. An adjunct move with this is to close all other open apps than the Adobe suite you are using. Photoshop has a 'Performance' Pane in the Photoshop —> Preferences menu. Go there and make sure Ps can "breathe," by giving it at least the recommended minimum RAM. Also set the 'Scratch Disks' Preference to the fastest drive you have, or at least a faster drive than a conventional hard drive.

The Apple M1 SOC mitigates this need for RAM by sharing a "unified" pool of memory with the CPU, GPU, and Neural Engine, so it swaps data much less often. This reduces I/O dramatically.

A graphics processor improves rendering speed, but does little or nothing for data I/O speed, which is almost always a data storage and memory swapping issue. I/O can seriously affect the flow of data to and from the graphics processor, so unless you can feed that GPU as fast as it can eat, it isn't all that helpful.

A faster processor helps with computational tasks, but there is far more data I/O in digital imaging than there is anything else. Most of the time, the processor is sitting, waiting on data.

Probably by the end of October, we shall see Apple's next generation of Apple Silicon Macs, featuring M1x processors. Long rumored to be up first are 14" and 16" MacBook Pros. They will feature a completely new design, bring back some legacy ports and the MagSafe charger connection, come with new display technology, and of course, the extended capability processor, M1x. Beyond those, still to come are a new Mac Mini, new MacBook Air, larger (pro?) 30" or 32" iMac, and a new Mac Pro, probably all of which are coming by 12/2022.

That said, the M1 MacMini, MacBook Air, 13" MacBook Pro, and 24" iMac are killer machines.

I have the M1 Air with 8 core CPU, 8 core GPU, 16 core Neural Engine, 16GB Unified Memory, and 1TB SSD. It smokes most other hardware under the $1400 I paid for it, refurbished. It has NO FAN, but I haven't been able to choke it or get it even mildly warm yet, even rendering a 12-minute 4K video. It renders a 292MB 16-bit TIFF (or an 8-bit JPEG of the same raw file) in well under three seconds. Critics and skeptics had me cautious at first, but dozens of glowing reviews have compared this machine against many Intel Macs and PCs. Most of the time, it comes out ahead on most tests. You have to add a third party graphics card to a PC to beat it.

Battery life of both M1 MacBook Air and Pro is amazing. M1 is far more efficient than Intel processors, so over ten hours of real world use is not at all unusual.

The chief drawbacks of M1 are its "sealed box" design (get the largest memory and internal storage configuration you think you might need, because it CANNOT be upgraded), and the lack of ports. You'll need a hub, dock, or adapter dongles to connect things. When it dies in a few years, the battery IS replaceable... with removal of the bottom panel. iFixIt.com has replacements, guides, and tools.

The M1 does throttle back a smidge under heavy tasks, but not so badly that it's a meaningful annoyance. The M1 Air, without a fan, is maybe 12% to 15% slower than the Pro for extended video rendering or 90-track audio mixing. (The base M1 Air at $999 can render over 90 tracks of heavily processed audio. It's $999 Intel predecessor with the same 8GB RAM and 256GB storage could handle 8 tracks, if you were lucky!)

you need a new computer. The m1 are great. Staying with a desktop, an imac 27" with as many core cpu's as you can afford & they have. At least 16gb of ram , but I suggest 32gbof ram. At least 4gb of dedicated gpu. Get 8, = would help future proof . At least 1tb of a fast M2 nvme ssd. Believe it or not yoiur cpu might be the most important item here. Apple = probably over $3k + Apple care. If you have the money , it is worth it when your not sitting there waiting for your photo adjustments to process or watching the computer screen go wacky!

https://www.pugetsystems.com/ cliick on solutions & follow the drop down to LR &PS & read the articles

What burke said if your going a different route. definitely cheaper with the M1. mini + screen unless you can use the one on your imac. m1'sa re suppose to be fast.

you need a new computer. The m1 are great. Staying with a desktop, an imac 27" with as many core cpu's as you can afford & they have. At least 16gb of ram , but I suggest 32gbof ram. At least 4gb of dedicated gpu. Get 8, = would help future proof . At least 1tb of a fast M2 nvme ssd. Believe it or not yoiur cpu might be the most important item here. Apple = probably over $3k + Apple care. If you have the money , it is worth it when your not sitting there waiting for your photo adjustments to process or watching the computer screen go wacky!

https://www.pugetsystems.com/ cliick on solutions & follow the drop down to LR &PS & read the articles

What burke said if your going a different route. definitely cheaper with the M1. mini + screen unless you can use the one on your imac. m1'sa re suppose to be fast.

you need a new computer. The m1 are great. Staying with a desktop, an imac 27" with as many core cpu's as you can afford & they have. At least 16gb of ram , but I suggest 32gbof ram. At least 4gb of dedicated gpu. Get 8, = would help future proof . At least 1tb of a fast M2 nvme ssd. Believe it or not yoiur cpu might be the most important item here. Apple = probably over $3k + Apple care. If you have the money , it is worth it when your not sitting there waiting for your photo adjustments to process or watching the computer screen go wacky!

https://www.pugetsystems.com/ cliick on solutions & follow the drop down to LR &PS & read the articles

What burke said if your going a different route. definitely cheaper with the M1. mini + screen unless you can use the one on your imac. m1'sa re suppose to be fast.

"I recently bought an M1 MacBook Air. I used Black Magic Disk Speed Test to clock the performance of my drives. Here are sample results:

Internal 1TB SSD: Write: 3265 MBPS Read: 2982 MBPS

External 2TB Samsung T7 (USB 3.2 connection): Write: 665 MBPS Read: 691 MBPS

External 3TB OWC MercuryElitePro 7200 RPM conventional drive: Write: 32.3 MBPS Read: 30.3 MBPS

The math boils down to this:

My external conventional hard drive is only ONE PERCENT the speed of my computer's internal SSD!

My Samsung T7 USB-C drive is only 20%/23% the speed of my computer's internal drive."

Thanks so much for the comparison. I was surprised that the Samsung T7 was so much slower (comparatively) than the internal SSD. I'm accustomed to using an aging Dell XPS desktop with replacement Samsung internal SSDs and find the new M1 Apple MacBookPro to be so much faster, regardless of whether I save to the internal or external SSD.

Note the date of this article: November, 2020. A lot has happened since then…

We’re on MacOS Big Sur 11.6, about to see MacOS 12.

Most mainstream apps are now fully updated for Apple Silicon, but were running in x86 Rosetta II emulation on beta MacOS software in the time frame this review was written.

https://isapplesiliconready.com/

The premise that folks would replace a desktop with a laptop is just weird. The vast majority of Internet review sites more realistically compare the M1 with other laptops (Mac and Windows) in similar price ranges.

The site I follow the most is MaxTech, a YouTube review site run by working photographers and videographers.

https://youtube.com/c/MaxTechOfficial

They test laptops from Apple, Dell, HP, Toshiba, LG, Zephyrus, Samsung, Microsoft Surface, and on and on. They run all the usual benchmarks, adding real world tests of Lightroom Classic, Photoshop, Premiere Pro, DaVinci Resolve, Final Cut Pro, and various browsers, plus some games, where appropriate (spoiler, the M1 is a mediocre gaming machine).

There are dozens of other review channels. Before buying my MacBook Air, I must have watched 30 reviews. Mentions of positive attributes far outweighed the negative ones.

The second generation Apple Silicon machines are in production now, and likely to be available in late October or November. The M1x and M2 designs designs are all new, and should kick the performance needles up several notches.

Well, I’d be the first to point out the Puget systems is in the business of selling custom PCs, so they may be a bit biased, but the benchmarking is just 10-11 months old, and are you suggesting that a rev in the OS mitigates an almost 2x difference in performance on benchmarks that are not “ported” to a specific CPU/OS?

Actually, I spent some time trying to find current benchmarks comparing an M1 system to Intel, and this was the most relevant I could find. Rather than a UTube video, can you point to a written review by a reputable publication, because I would really like to see some definitive information by someone who doesn’t have a vested interest in the outcome - either Mac or PC fanboys.