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Rob.G

macrumors 6502a
Original poster
Jan 17, 2010
530
85
Arizona
This is the second night in a row. After 5 pm, my Mac gets really slow. Last night I thought it was just having wifi issues, but I have two Windows laptops, an Apple TV, two iPads, my iPhone, an Apple TV and a PS4 all using it and they're running just fine. And fwiw, none of them are using any bandwidth at this time. Finally last night I powered it off and said to heck with it. This morning it was back to its snappy self.

BTW this is a 2019 16" MacBook Pro, 8-core i9, 64gb RAM, 2tb SSD that I've had for about six months. Until yesterday, it's been completely flawless.

Anyway.. so after 5 pm, it started doing it again. I've already shut it down once. But what I've discovered is that the whole machine has slowed WAY down. Yet Task Manager does not show anything using any notable CPU power. The fan is purring along quietly at 1800 rpm (can't even hear it). it's just SLOW.

So I put it on my iPhone hotspot. Yep, even on that, it's about 1/10th the speed as it should be, network-wise. Try to launch an app? Very slow. Click on an icon in the dock. Nothing happens. A moment later, it bounces a few times. Then a few seconds later, the app loads. Normally, it's instantaneous.

Last night I reset the NVRAM and the SMC; neither did any good.

I tried different browsers... all have the same issue.

More than anything, it's wifi speed that is suffering. It's "rate" of "slowness" is greater than the slowness of the Mac itself, though the Mac itself is still slower than it should be. And it's not a beachball thing either. I'm not getting lots of beach balls. It's just... slow to respond and slow to function.

I don't get it. Over ten years of owning Macs and this is a new issue... btw I'm still on Catalina. Haven't really wanted to update to Big Sur yet.

Anybody else ever seen an issue like this? Actually, in the few minutes that it's taken to write this, the computer itself has sped up a bit, but still isn't 100% what it normally is. Network speed (via wifi) is still pathetic.
 
Hi,

I have the same problem. Every day at 5 pm the system slows down. Yesterday I had in addition a system crash (image). Did you find a solution?
B0A7D781-6BE7-4C69-8776-55AAEDF43E64.jpeg
 
I think I have a bad wifi card in my Mac. I ordered an RJ45 adapter and it runs just fine being plugged in. But on wifi, it's awful.
 
do you have night shift enabled? on earlier versions, my mac used to slow down when night shift was doing its business. Havent seen it happen in recent versions though (but im on mojave and never upgraded past it)
 
Night shift in Mojave 10.14.6 was broken and if you used an external monitor tried to flip the resolution of the monitor every few milliseconds. That resulted in the Windowserver process going high CPU when night shift enabled. I recent rolled back a mbp to test 10.14.5 which was perfect but then let it upgrade to 10.14.6 which has the issue. Complete new install and nothing else installed on the machine. So the end Mojave release was broken unless all you used it for was a standalone. Catalina took over from those display issues and introduce alot more issues for extenal monitors but the nighshift issue I've not seen....just kernel panics, beach balls and resolutions being incorrect etc. Hence the reason to head back to 10.14.5. Last version that seems to work with external monitors properly on my 2017 mbp.
 
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