2019 Mac Pro 3.5GHz 8-core and Tahoe: A tale of sluggishness

[Auggie]

Ever since installing Tahoe, its interface has been doggedly slow on my 2019 Mac Pro with noticeable sluggishness waiting for interface elements to respond or draw out completely. At first I thought it was because it was a beta-release at the time. But nope; with the official release of Tahoe the sluggishness remained.

It's a standard 3.5GHz 8-core Xenon, 96GB RAM, AMD Radeon Pro W5700X 16GB, and 4TB Apple SSD.

Apple stated that this will be the last year this model will be officially supported; next gen macOS next year will only support Apple M-chips.

But I can't believe that there's been no optimization whatsoever in this last Intel-version of macOS.

Is anyone else with a 2019 Mac Pro experiencing similar sluggishness?

 

[jjhoekstra]

That is a 6 year old computer... The reason why Apple moved to the ARM infrastructure was the lack of innovation and development of Intel. In it's time it was a decent processor, now it is only a decent room-heater. To be honest, I still have a similar rig running, to do some batch processing of videos. Mainly out of sentimental reasons. What you could do is install Linux on it. The result is a decent and fast computer. But without the OSX advantages.

 

[bradman83]

Are you on 26.1 or still 26.0.1? The former definitely offered an improvement in terms of performance (26.0 was sluggish across the board for all machines). I'm on the 26.2 beta and it feels even better.

 

[Ries]

That is a 6 year old computer... The reason why Apple moved to the ARM infrastructure was the lack of innovation and development of Intel. In it's time it was a decent processor, now it is only a decent room-heater. To be honest, I still have a similar rig running, to do some batch processing of videos. Mainly out of sentimental reasons. What you could do is install Linux on it. The result is a decent and fast computer. But without the OSX advantages.

The Pro W5700X has the same metal performance as an M4 Pro gpu. There is no reason for it to be sluggish….

 

[turbineseaplane]

That is a 6 year old computer... The reason why Apple moved to the ARM infrastructure was the lack of innovation and development of Intel. In it's time it was a decent processor, now it is only a decent room-heater. To be honest, I still have a similar rig running, to do some batch processing of videos. Mainly out of sentimental reasons. What you could do is install Linux on it. The result is a decent and fast computer. But without the OSX advantages.

What?
🤨 🧐

A 3.5GHz 8-core Xenon, 96GB RAM, AMD Radeon Pro W5700X 16GB, and 4TB Apple SSD should run ANY OS absolutely butter smooth.

The problem here is Tahoe and Apple's hot garbage software quality.

 

[Auggie]

The Pro W5700X has the same metal performance as an M4 Pro gpu. There is no reason for it to be sluggish….

What?
🤨 🧐

A 3.5GHz 8-core Xenon, 96GB RAM, AMD Radeon Pro W5700X 16GB, and 4TB Apple SSD should run ANY OS absolutely butter smooth.

The problem here is Tahoe and Apple's hot garbage software quality.

Yea, the 2019 Mac Pro is not an old G5 or PowerBook: This is still serious hardware. I didn't want to respond to an ignorant post...

 

[conmee]

While not a Mac Pro, my 2019 MBP 2.4Ghz, 64GB, 5500M 8GB felt sluggish as well. Even connected to a 120Hz monitor the animations were not smooth (except for Notifications and widgets which would slide in from the right so smooth, I would check the weather and stocks just to see lol). Mission Control was the worst as any time I had more than two windows open, my MBP would struggle to make the Mission Control animation smooth. My 2019 15” with Vega 20 4MB doesn’t run Tahoe but Sequoia is snappy and all windows pop and Mission Control is satisfyingly smooth as well. Given how sluggish my 16” is with animations, I can see why Apple dropped the 2019 15” from support. Going to stick with Sequoia (and iOS 18) for two more years and then retire my Intel MBPs. Hopefully by then Apple will have refined Liquid Glass and a 16” M7/M8 should be a nice upgrade. And maybe even a 20th Anniversary iPhone mini as well. Ha!

 

[bzgnyc2]

FYI some workarounds available now:

Save As and Open Dialogs Are Slow on macOS Tahoe

Fix slow Save As and Open dialogs on macOS Tahoe with clear steps that address WindowServer lag, GPU overload, and rendering bugs.

www.macobserver.com

Some fixes coming in 26.2:

macOS Tahoe 26.2 Ends the Electron Lag That Slowed Your Mac

macOS Tahoe 26.2 fixes Electron slowdowns, restores smooth scrolling, blocks risky private API misuse, and improves system performance for every Mac user.

www.macobserver.com

While the above is about restoring performance for Electron apps, my guess is they will end up tweaking a number of things under the hood that should improve performance for other apps, too.

Agree with the general sentiment though that there's no good reason for that hardware (or even a fraction of that hardware) to be sluggish. Really any computer faster than a Core2 Duo should be able to run a UI/UX buttery smooth and even some 3D.

 

[galad]

Unfortunately that Xeon has got only 1/3 or less than the single-core performance of an Apple Silicon CPU, and macOS 26 has still many performance issues. So while it could be getting better, even the lower end Apple Silicon chip will still be much more responsive.

 

[benwiggy]

It's well worth testing the behaviour in a brand new user account. This will confirm whether the problem is at the system-level, or the user level. It could be any number of things -- Login Items that are no longer compatible with the new OS, corrupt databases, preferences, etc.

A problem after installing a new OS doesn't necessarily mean that the OS is "the problem" -- merely one of several factors.

It could be Tahoe itself; or it could be something else. If it is Tahoe, then newer builds might improve matters.

 

[SDAVE]

I am on 28c 7,1 with 6900XT and I have the same issue. It's definitely related to optimization. I installed .2 Beta 3 and it's much better, and it should get better over time and I have a feeling Apple will REALLY optimize this since Tahoe is EOL on Intel Macs (if you remember, Leopard was the last PowerPC supported OS and it was very optimized for that at EOL). Snow Leopard removed PowerPC architecture and was highly optimized for Intel and considered one of the best macOS releases in history. I have a feeling Apple will TRULY optimize macOS in macOS 27 for M series chips, but us Intel users will be SOL.

The sluggishness is related to Liquid Glass because it's doing a lot of work even when idle. There's all kinds of effects they use like real blurs, chromatic abberation, reflections, refractions, etc for the UI now. When you use windows, drag, open control center, the GPU usage spikes quickly and there's a delay to that due to bad optimization.

I also suspect there's many memory leaks throughout the system, including Save As dialog boxes (related to WindowServer) and even apps like messages. These will be patched up in later releases of Tahoe.

Historically .0-.3 releases of macOS are pretty bad, since they keep adding new (most of the time useless) features and breaking things with the yearly update cycle.

Quick (Temporary) Fix:

• Install .2 Beta 3 (Beta 4 should come next week and then Beta 5 and final in mid December)
• Enable "Reduce Transparency" under Accessibility > Display
• Enable reduce motion in "Reduce Motion" under Accessibility > Motion
• Disable transparent icons if you have that enabled under Appearance > Icon & Widget Style > Set to "Default"
• Disable window tinting under Appearance > Tint window background with wallpaper color

The above did it for me and it feels more like Sequoia. I will re-enable Liquid Glass when things are more optimized. Turning on Liquid Glass slowed my system so much that it slowed down my work overall, especially in demanding apps like Creative Cloud.

To counter this issue with Intel Macs, my M1 Max (maxed out GPU/CPU with 64GB RAM, 2TB drive) I have no issues with lags at all, even when connected to Dual 5k Studio Displays. So it's definitely related to Intel optimization because the 6900XT is a super fast GPU and faster than whatever Apple provides. RAM might be slower than GDDR5 on M class Macs, of course.

 

[bzgnyc2]

Unfortunately that Xeon has got only 1/3 or less than the single-core performance of an Apple Silicon CPU, and macOS 26 has still many performance issues. So while it could be getting better, even the lower end Apple Silicon chip will still be much more responsive.

While Apple Silicon are great chips, the Xeon in the Mac Pro is actually about 60% of an M1 on Geekbench single-core. Newer Apple Silicon are multiple times faster on single core and all sorts of other good stuff but the low-end wasn't that much of a leap.

However, all these chips have more than enough power to handle UI/UX responsively if reasonably programmed. The performance issues of macOS 26 as you mentioned are the root problem here. What is macOS doing for us in these cases that a Core2 Duo (or even G4) with an HDD didn't handle just fine back in the day?

 

[MarineBand5524]

How often do you go into Disk Utility and run First Aid? How often have you or do you back up your machine and then completely just start from scratch, set it up as a new machine, then drag back your programs and files from backup?

 

[SDAVE]

How often do you go into Disk Utility and run First Aid? How often have you or do you back up your machine and then completely just start from scratch, set it up as a new machine, then drag back your programs and files from backup?

I do it every couple of months, but I boot into recovery mode so it runs without files being locked

For backups I just use Time Machine, honestly haven't had to 'start from scratch' in a long time, I don't think it's necessary nowadays.

 

[MarineBand5524]

I do it every couple of months, but I boot into recovery mode so it runs without files being locked

For backups I just use Time Machine, honestly haven't had to 'start from scratch' in a long time, I don't think it's necessary nowadays.

You'd be surprised how much it clears and cleans out to start from scratch.

 

[SDAVE]

You'd be surprised how much it clears and cleans out to start from scratch.

Oh for sure, I used to do this a lot back in the day. It's pretty easy to restore from Time Machine, but it takes time to set everything up from 0. I guess I'm lazy nowadays.

 

[Auggie]

How often do you go into Disk Utility and run First Aid? How often have you or do you back up your machine and then completely just start from scratch, set it up as a new machine, then drag back your programs and files from backup?

For me, I had so many stability issues with the initial beta I did a complete wipe and reinstall of Sequoia first on the Apple T2-SSD's then migrated from a backup. This was to confirm whether it was Tahoe or a mucked up install.

This clean wipe and Sequoia migration worked just fine with no issues. Then after a few weeks, I took the plunge again into Tahoe and the sluggishness returned.

 

[Auggie]

FYI some workarounds available now:

Save As and Open Dialogs Are Slow on macOS Tahoe

Fix slow Save As and Open dialogs on macOS Tahoe with clear steps that address WindowServer lag, GPU overload, and rendering bugs.

www.macobserver.com

Some fixes coming in 26.2:

macOS Tahoe 26.2 Ends the Electron Lag That Slowed Your Mac

macOS Tahoe 26.2 fixes Electron slowdowns, restores smooth scrolling, blocks risky private API misuse, and improves system performance for every Mac user.

www.macobserver.com

While the above is about restoring performance for Electron apps, my guess is they will end up tweaking a number of things under the hood that should improve performance for other apps, too.

Agree with the general sentiment though that there's no good reason for that hardware (or even a fraction of that hardware) to be sluggish. Really any computer faster than a Core2 Duo should be able to run a UI/UX buttery smooth and even some 3D.

Wow. Thanks for corroborating my gut feeling that this is a systemic issue.

I can only be hopeful that Apple will get this right and invest the resources to restore some semblance of performance for the last-of-its kind Intel Mac Pro...

 

[hieubui]

I'm on an M1 Pro with 32GB of RAM and get downvoted to oblivion every I mention sluggish performance on Tahoe LOL