[wasyl]

I wish someone did an analysis to determine why my intel-based macbook is so incredibly laggy all the time, even after fresh system installation. I can't shake the feeling that Apple Silicon is so much faster that performance issues just got into the system without anyone at Apple bothering to fix them, and Intel macs suffer as a result.

[monocularvision]

My wife’s Intel-based laptop got considerably slower in the last year or so. I tried everything I could but nothing seemed to return it to its original performance.

Then she got a warning that the battery needed servicing. After getting it replaced (and the Apple employee warning us several times that it might not help performance), the laptop was back to its previous state. My theory is that the battery running warmer was causing the CPU to throttle. Or perhaps cleaning out the machine while replacing the battery helped it thermally. Or maybe both.

[wasyl]

Interesting, how old was it? Do you recall how many cycles the battery was at? Unfortunately throttling is unlikely in my case, at least for the lagging I observe day-to-day, I don't see any throttling via `pmset -g thermlog`. I did wonder if changing thermal paste would help, but since I don't observe throttling I'm not sure it would

[monocularvision]

I believe we purchased it around 2018 or so. I didn’t look at the power cycles, just got the warning about needing maintenance.

[rspoerri]

It's overheating and the (my) problems came from:

- loading the battery and powering the device

- high gpu power usage when plugging in a external monitor

- cpu power usage

- bad cooling which must be cleaned often

My recommendations:

Plug in the power from the right side. Afaik the thermal throttling kicks in sooner if you have it plugged in on the left.

Clean the device. Unfortunately it really sucks to open it. You will need special tools and lots of trust in the spaghetti monster that you dont break anything.

Cpu power usage can be lowered by using any of the tools:

https://github.com/sicreative/VoltageShift

https://volta.garymathews.com/ (most probably not working anymore)

Unfortunately in later updates apple prevented undervolting the cpu so it's (VoltageShift) use is limited now. But i was able to limit the power usage to 5W, which somehow helped keeping my device cooler. Be aware that you need to disable quite a lot of security measures to install Voltageshift.

Apparently having power saving active even when plugged in helps keeping the cpu and gpu cooler. I did not test this extensively because i switched to a m2.

A big problem comes from the gpu, if you have an external monitor plugged in, the video drivers start using 10W+ which causes problems when you are loading the battery as well. There are a lot of discussions on what causes the problems, it has to do with the drivers and some screens causing it to use way more power then needed. It can help to close the lid of the macbook while working with a external monitor.

[wasyl]

Thanks for the suggestions, this all sounds plausible, however: - I routinely clean, or at least de-dust everything accessible after removing back cover - the lag is there always, even right after resuming the mac, before any thermal throttling should be kicking in. I also don't observe throttling with `pmset -g thermlog` - I'm not using an external monitor

At this point the most likely culprit is the battery, mine is at 789 cycles although the condition is reported as "normal". I wish it were possible to confirm whether battery is an issue before spending couple hundred $ on replacement though