M1 MacBook Air is sluggish after macOS Tahoe update with 8GB memory

Your testing points to a substantial difference between macOS Tahoe and Sequoia on your M1 MacBook Air, but it does not yet establish that 8 GB of memory is the bottleneck.

Apple officially supports the M1 MacBook Air (2020) on macOS Tahoe, so your configuration is within Apple's supported hardware range. (Apple Support)

The most significant part of your testing is that the same physical Mac is smooth and responsive on Sequoia but consistently sluggish on Tahoe. You have also tested Tahoe after resetting the Mac and setting it up as new, and you allowed substantial time for indexing to finish. 

This is important because restoring or migrating from a previous macOS installation can transfer applications, user accounts, settings, and other data. 

Consequently, a migrated environment can potentially reintroduce an application, setting, or other component that could contribute to a problem that would not occur on a genuinely clean installation.

Apple documents what Migration Assistant transfers here. (Apple Support)

Because you also tested Tahoe as a new installation without restoring your previous environment and still experienced the same sluggishness, the problem cannot reasonably be attributed simply to something inherited from your Sequoia installation. That strengthens the evidence for a Tahoe-specific issue on this particular Mac/configuration.

The approximately 6 GB of memory used after startup should not be treated as proof that the 8 GB is exhausted. Apple explains that macOS uses available memory efficiently, including for cached files. The relevant measurements are Memory Pressure, Swap Used, and compressed memory. Persistent yellow or red memory pressure, particularly while the lag is occurring, would provide much stronger evidence that the 8 GB configuration is contributing to the problem. (Apple Support)

Your Liquid Glass explanation is possible, but it should remain a hypothesis rather than a conclusion. Tahoe's redesigned interface changes the graphical workload, but your observations alone cannot establish that Liquid Glass itself is consuming enough GPU or memory resources to cause the system-wide slowdown.

A useful test is to enable Reduce Transparency and Reduce Motion in System Settings → Accessibility → Display. If responsiveness improves substantially, that would provide evidence that Tahoe's visual effects are contributing to the problem. It would not, by itself, prove that GPU usage or 8 GB of memory is the underlying bottleneck.

The 81% battery health figure also does not, by itself, explain the Tahoe-versus-Sequoia difference. It is worth checking whether macOS reports Normal or Service Recommended battery health rather than treating the percentage alone as evidence of a performance problem.

The most useful test now is to open Activity Monitor while a lag spike is actually occurring. Check Memory Pressure and Swap Used, but also CPU, GPU, and Disk activity and whether a particular process becomes unusually active at the same time. This can help distinguish memory pressure from CPU, graphics, storage, or another system-process issue.

Because the M1 MacBook Air's unified memory is not user-upgradable, sustained memory pressure would be significant evidence that the 8 GB configuration is a genuine limitation for that workload. Conversely, if Memory Pressure remains green and swap activity is low while the system is lagging, the evidence for 8 GB being the cause becomes considerably weaker.

Therefore, the most accurate conclusion is: 8 GB may limit the performance headroom of the M1 MacBook Air under Tahoe, but your current evidence does not prove that it is the bottleneck. What your testing demonstrates much more clearly is a substantial Tahoe-versus-Sequoia performance difference on the same Mac. Because the problem also occurs on a clean Tahoe installation, migration from Sequoia is unlikely to be the explanation. Activity Monitor measurements during an actual lag spike are needed to determine whether memory pressure, graphics, CPU, disk activity, or another Tahoe process accounts for the difference.

Apple's relevant documentation includes Transfer to a new Mac with Migration Assistant, which explains what Migration Assistant transfers, and Restore your Mac from a backup, which explains restoring information from a Time Machine backup. (Apple Support)

As suggested by myself and Owl, check the colour of the memory pressure when you are experiencing a performance lag.

If the pressure is actually green your memory is unlikely to be the culprit.

One possibility could be thermal throttling although that should not be occurring when the machine is under a light load unless you are working in an incredibly hot place or have your MBA sinking into a carpet or blanket which can cut off the ventilation.

Because it is fanless you should always have it seated on a hard surface and out of direct sunlight etc.

If Liquid Glass really is the cause of the problem you can't disable it but you can reduce its impact on processing power.

System Settings>Accessibility>Display . . . . toggle ON "Reduce Transparency".

System Settings>Appearance . . . change Liquid Glass from Clear to Tinted. Also if you go lower down you can turn off "Tint window background with wallpaper colour"

System Settings>Accessibility>Motion . . . switch ON "Reduce Motion".

These adjustments do not disable LG completely but make the OS look more like Sequoia and should reduce the LG's need for extra processing power.

Download etrecheck, run it and post the results here.

https://etrecheck.com/en/index.html

You cannot copy and paste the report here because it is too long but there are instructions with the app on how to get the whole report posted.

I suggest you also copy your post to the Tahoe forum . . . the more knowledgeable people who see it the better.

Hello,

I understand your frustration, and it’s totally valid. 8GB of RAM is definitely a hard limit, and it makes sense your MacBook Air is very laggy. Your point that MacBook Neo was made for Tahoe is also 100% valid. Honestly, as a power user of macOS, I will tell you right now:

1. Open activity monitor
2. Go to the Memory section
3. on the bar under window management (the quit, minimize and maximize) there is a word which says memory, and shows "mem" of you have the activity monitor maximized.
4. on that tab, make sure the arrow head is pointing DOWN to ensure most RAM consuming is on the top
5. Check things that use most RAM, and quit them if not needed
6. Also, check memory used and swap memory, this plays a big role as the SSD is slower than the RAM.

In my case:

Hope this helps,

Thanks, 

Memory usage is confusing to many people and they get the wrong impression that they haven't got enough.

Macs are designed to use most of their memory even when idling . . . think of a car engine which has all its cylinders firing whether it's idling or going at full speed.

Using most of the memory all the time means that your Mac can accelerate rapidly the moment a stressful task is thrown at it.

If you had 32 GB RAM you would probably see most of it being used whilst idling.

For the first 20 years of owning a Mac I kept looking at the memory usage and feeling there wasn't enough.

Take a look at my M4 with 16 GB RAM. At the moment I am just sitting watching the screen and 75% of my memory is being used.

The important thing is the Memory Pressure which is shown by the green area. As you increase the workload that will turn yellow and when you are really stressing your machine it will go red.

Anyway you may have noticed that I am the only one replying after several hours which is why I advised you to copy your question onto the Tahoe forum which has many more users.

P.S. I noticed that I had several apps open so I closed them and the memory used dropped slightly to just under 75% . . . a negligible decrease.

Sorry if its a bit of a late reply, and please feel free to ask for more info

Hi,

I've been using Mac mini 2020 8GB RAM, 512GB Storage with Golden Gate, though it works smoothly.