Battery drain and high CPU usage after Tahoe update

Your EtreCheck report does not suggest a failing CPU, SSD, or a hardware defect.

The strongest clue is the repeated high CPU usage from WindowServer after upgrading to macOS Tahoe.

Quote from @ Grant Bennet-Alder

" WindowServer is the task that makes sure the right stuff is in every window, manages multiple windows in multiple positions on the screen, possibly overlapping or not, and generally manages all issues related to drawing the stuff on the screen. " End Quote 

Your MacBook Pro 16-inch (Intel, 2019) uses both Intel UHD 630 graphics and an AMD Radeon Pro 5300M GPU. Since Tahoe was installed, the system appears to be spending more resources on graphics/compositing tasks, which matches your symptoms: fans ramping up during simple tasks like YouTube playback, high WindowServer activity, and very poor battery life.

Ryujinx is unlikely to be the original cause because your issue started before you installed it. The EtreCheck history also shows WindowServer high CPU usage beginning shortly after the Tahoe update.

Your battery is also a factor. A cycle count of 1291 is above the typical design target for this generation of MacBook Pro batteries. macOS reporting “Normal” health does not mean the battery still has its original capacity. A worn battery combined with increased GPU usage can easily result in much shorter runtime.

if you see battery 'Service Recommended' on your Mac laptop

The first things I would try are resetting the SMC, testing with Automatic Graphics Switching disabled, and checking whether the problem happens with only the built-in display. Apple’s instructions for resetting the SMC on Intel Macs are here: Reset the SMC of your Mac

I would also check Activity Monitor while the problem occurs and look specifically at WindowServer, Safari/WebKit, and GPU usage. Apple’s guide for checking Mac performance is here: Activity Monitor User Guide

If the issue continues, test with a fresh macOS user account. If WindowServer remains high there, the problem is likely system-level and related to Tahoe’s graphics stack. If it disappears, a user-level item such as an extension, driver, or background utility is more likely.

Your report does show some older third-party components (such as Java, Huion software, and old launch agents), which are worth temporarily removing or disabling for testing, but nothing in the report clearly identifies one of them as the cause.

I would avoid reinstalling macOS or blaming individual apps until these tests are done. Based on the timing and the WindowServer behaviour, a Tahoe graphics/power-management issue is the most likely explanation.

The battery is reported as healthy (although 1,291 cycles means it may have reduced capacity).

Apple Batteries are designed for 80% of Capacity or about 1000 Full Cycles before the battery needs servicing or replacement

The symptoms you describe are more consistent with a macOS Tahoe graphics/background process issue than a hardware failure.

The main thing that stands out is WindowServer. EtreCheck shows WindowServer repeatedly using high CPU, and that matches your experience with fans spinning during simple tasks like YouTube playback. 

On your MacBook Pro 16-inch Intel model (MacBookPro16,1 with Radeon Pro 5300M), WindowServer problems can be related to the graphics system, Metal, or GPU acceleration after a major macOS update.

I would first try running without anything that modifies graphics or system behaviour. 

Temporarily uninstall Mac Fan Control, quit Telegram, and avoid Firefox for testing. 

Also remove old unused components such as the Java browser plugin if you no longer need it. Then restart and test battery life and fan behaviour.

The kernel panics are the most important issue. Four panics in two days are not normal. Please check:

Finder >> Go >> Go to Folder >> /Library/Logs/DiagnosticReports/

Look for files beginning with “panic-full” and share the latest one. The panic log should reveal whether the cause is related to the AMD GPU, Intel graphics, a driver, or another system component.

A few Apple troubleshooting steps are also worth trying: Check whether macOS has detected hardware problems: Use Apple Diagnostics to test your Mac

The next useful piece of information is the panic-full log because it should identify the component causing the crashes.

if the user believes these current issues stem specifically from macOS 26 Tahoe.

For a thorough test of both Tahoe / Hardware and to  determine the root cause of all the computer issues.

Use the “Atomic” option

Apple Intel computers >>   Use Disk Utility to erase an Intel-based Mac followed by How to reinstall macOS

Always make a Time Machine backup before proceeding.

Run the computer without installing any additional software and without restoring from your Time Machine backups.

Run the computer in this mode for approximately 2 - 3 hours and report back if the previous issues reoccur.

Just a heads-up, the Atomic option in the above would likely be what an Apple Authorized Service Centre would recommend before they dive into a Hardware Evaluation of this computer. 

I have that same Mac, 2019 Intel 16" MacBook Pro, except mine is an i9. It is on Tahoe 26.6 and runs great! So the hardware can inherently handle Tahoe fine (I have experimented with different settings for the "liquid glass" elements and see little or no difference in performance).

I think Owl-53 has already made some great observations and suggestions.

My SSD shows 3000 MB/s for both write and read, I noticed yours is notably slower on writes. While I don't think that is indicative of SSD failure, it might be a symptom of impeded performance. My Etrecheck report says it is running "Good" while yours says "Below Average."

My Battery setting for the graphics is on "automatic switching" (for the two graphics options).

There is another setting for graphics handling when streaming and on battery power. It might slow your Mac down when on battery power, in an attempt to save battery energy.

My Mac is always connected to the charger when available. It has about 120 cycles on the battery. You have obviously been running on your battery a lot more, you have used almost 1300 cycles, which exceeds the spec for your battery (it should probably be replaced).

If your battery is losing capacity, your Mac will struggle when doing demanding chores and running off the battery.

Have you tried connecting to the charger whenever possible and running that way? Does your Mac still run fans and struggle when used that way?

The only time I hear my Mac's fans is (briefly) when doing a MacOS update or sometimes briefly during a Time Machine backup. Otherwise it is always silent. I have multiple browser windows open (a few dozen) and run Microsoft 365 apps, Adobe apps, and sometimes other programs like TurboTax. I sometimes view videos but never hear the fans when I do.

Thank you 👍 for the above info

Preface 

I have consulted an AI / LMM,  so take the below not an an Authoritative Source for accurate and reliable informations  

Yes. On the Intel-based 16-inch MacBook Pro with the Touch Bar (particularly the 2019 model), a failing battery can reduce overall performance even when the computer is plugged in and charging.

This happens because the system is designed to draw power from both the AC adapter and the battery during short periods of high demand.

If the battery is unable to provide supplemental power or has developed a fault, macOS may reduce CPU and GPU performance to maintain system stability and prevent unexpected shutdowns.

You can check the battery's condition in System Settings > Battery > Battery Health, or by running system_profiler SPPowerDataType in Terminal.

If the battery status is Service Recommended or reports a hardware issue, replacing the battery often restores normal performance.

For more information, see Apple's battery health documentation at About battery health management in Mac laptops and Apple's battery service information at Mac battery service and repair

Taking everything into account:

1. The age of the Intel-based MacBook Pro (16-inch, 2019), equipped with either the AMD Radeon Pro 5500M with 4 GB of GDDR6 memory and automatic graphics switching, or the AMD Radeon Pro 5300M with 4 GB of GDDR6 memory and automatic graphics switching.
2. The introduction of Metal 4 in macOS 26 Tahoe and its support for the AMD Radeon Pro GPU.
3. The battery's condition, with 1,291 charge cycles.
4. The fact that this is an Intel-based Mac.

You may be able to extend the usable life of the computer, provided there are no underlying hardware issues that require component replacement, which could add significant repair costs.

However, if you plan to continue using Apple computers and intend to upgrade to macOS 27 Golden Gate, it may be worth considering a move to an Apple Silicon Mac, as macOS 27 Golden Gate supports only Apple Silicon systems.

From what I have read, getting the most out of Apple Intelligence is generally expected to require at least an M3-based Mac with 16 GB of unified memory.

After carful re - examination of your Etrecheck Report

/Downloads/coconutBattery.app/Contents/Library/LoginItems/coconutBattery Menu.app

What does that application report for the 2 arrowed items in that image

The Design Capacity being that which I believe is what Apple says should be the Capacity when branded new

The Full Charge Capacity is what the Battery can attain

I am speculating here and can not independently verify this

In specific regards to the interactions between Apple's Metal 4 ( Tahoe ) and the AMD Radeon Pro 5500M with 4 GB of GDDR6 memory and automatic graphics switching, or the AMD Radeon Pro 5300M with 4 GB of GDDR6 memory and automatic graphics switching.

As for the battery, that is something you can do about ( at a cost to you )

Thank you too 👍

I am preparing a more extensive reply, which may or may not be welcome once it is completed.

So hold off whatever you are doing or thinking of doing at this time

+1 @ steve626

Thank you for adding your on-hand experience

🦉-53

emanuela87 wrote:

I ran the diagnostic and no problems were found as we supposed. Ref. code: ADP000

That is a good sign and that you for the updated into