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Brandon Miles

macrumors newbie
Original poster
Jun 20, 2020
18
1
Since Big Sur has be released my macbook runs 20°C hotter than usual. I use SMCFan control to measure temps and instead of sitting at 40°C idle its running at 60°C idle and on loads at 80°C instead of 50-60°C.

I haven't updated to Big Sur, I haven't downloaded Big Sur and have been using my mac the same amount before and after its release with concistient results.

I'm no conspiracy theroiest but since apple has been caught out before with intentially slowing down older machines especially iPhones I am curious to see if anyone has a similar issue or if anyone knows what might be causing issues for myself.

Cheers.
 

Brandon Miles

macrumors newbie
Original poster
Jun 20, 2020
18
1
40°C Idle? Never got that to work on my MacBook Pro early 2015. Recently applied new thermal paste.
Idling around 50°C. Now while browsing &charging around 60°C cpu average.
I used some overclocking thermal paste and gave the whole board a good clean and dusting about 4 months ago. Would highly recommend the NT-H2 or thermal grizzly.
 

juan985_Spain

macrumors member
Jun 30, 2019
67
30
expensive thermal paste, a good dusting and optimised programs help a lot. DisableTurboBoost plugin helps too since it doesn't overclock the CPU and drive itself to 100°C
I recently repasted my 2015 15" Macbook Pro. When IDLE normally stays at 47ºC. Maybe its running hotter as it is a quad core processor. I am also using Volta app (Working great in macOS Big Sur) to Undervolt the CPU and disable TurboBoost. It helps to lower load temp up to 20 degrees when performance is not a priority
 

Brandon Miles

macrumors newbie
Original poster
Jun 20, 2020
18
1
I recently repasted my 2015 15" Macbook Pro. When IDLE normally stays at 47ºC. Maybe its running hotter as it is a quad core processor. I am also using Volta app (Working great in macOS Big Sur) to Undervolt the CPU and disable TurboBoost. It helps to lower load temp up to 20 degrees when performance is not a priority
yea mines just a basemodel so less TDP probably so runs lighter than your quad. I'll look into the volta app that seems interesting!
 

juan985_Spain

macrumors member
Jun 30, 2019
67
30
yea mines just a basemodel so less TDP probably so runs lighter than your quad. I'll look into the volta app that seems interesting!
Just an update, my Macbook retina 2015 15" is in the upper 30´s when idle. However just using Safari or Mail shoots the temperature to de 50´s. So i believe yours should idle in the 40´s as you stated.

Captura de pantalla 2020-11-28 a las 11.37.30.png
 

Brandon Miles

macrumors newbie
Original poster
Jun 20, 2020
18
1
Just an update, my Macbook retina 2015 15" is in the upper 30´s when idle. However just using Safari or Mail shoots the temperature to de 50´s. So i believe yours should idle in the 40´s as you stated.

View attachment 1681732
This is the issue. I haven't updated to big sur, and before it was fully released my mac was able to sit at 40°c. Since big sur has been released it keep ramping up temps. Which is I'm asking if anyone else has seen any weird behaviour. Apple has done it before where they've intentionally handicapped older models but I don't have any concrete evidence with this
 

sgtaylor5

Contributor
Aug 6, 2017
446
224
Cheney, WA, USA
Brandon, What OS version are you using? I've been trying out High Sierra vs Catalina, and I'm using Macs Fan Control to run my fan at 3500 RPM in both versions. I'm typing in Catalina Safari with MailMate and DEVONthink running in the background on my late-2013 i5 MacBook Pro and my background temp (CPU PECI) is 38C.

I thought that High Sierra was lighter in weight than Catalina, but when I ran High Sierra last night (external HDD over USB 3), it seemed the heat signature was the same as Catalina, which surprised me. The first time I upgraded from Mojave to Catalina, my MBP was running way hotter than it is now. I went to clean install High Sierra for a while. This time I clean installed Catalina to an external disk, then used Migration Assistant from High Sierra. I know that's a lot of work for me, but I'm getting a better idea of what to think about macOS performance: clean install is better than upgrading in place, because it keeps the performance and heat signature the same between OS versions.
 

Brandon Miles

macrumors newbie
Original poster
Jun 20, 2020
18
1
Brandon, What OS version are you using? I've been trying out High Sierra vs Catalina, and I'm using Macs Fan Control to run my fan at 3500 RPM in both versions. I'm typing in Catalina Safari with MailMate and DEVONthink running in the background on my late-2013 i5 MacBook Pro and my background temp (CPU PECI) is 38C.

I thought that High Sierra was lighter in weight than Catalina, but when I ran High Sierra last night (external HDD over USB 3), it seemed the heat signature was the same as Catalina, which surprised me. The first time I upgraded from Mojave to Catalina, my MBP was running way hotter than it is now. I went to clean install High Sierra for a while. This time I clean installed Catalina to an external disk, then used Migration Assistant from High Sierra. I know that's a lot of work for me, but I'm getting a better idea of what to think about macOS performance: clean install is better than upgrading in place, because it keeps the performance and heat signature the same between OS versions.
I think you're having a different issue to me, upgrading mac OS will definitely come with some performance sacrifices since a bunch of new features gets added with each version. If your upgrading rather than starting fresh you have all your old data on top of new data on top of new features so it will run hotter.

Dual booting is what I assume you're doing but that can also cause a slowdown if you're disk is quite full (default mac drives before the 2016 mbp are quite slow and use a slower connection) so if you're able to then clean install.

And if you have the tools and time spare, buy some decent thermal paste, some compressed air, a new high speed SSD and a kit to open your mac and replace the old hard drive, give it a dust and replace the old thermal paste. All of this will help your mac run faster and cooler so that you can run catalina at lower temperatures, thats how mines so low.


Just to clarify, my issue is with catilina about a year after using it. No issues, low temps, fans not even needing to run on idle. Then one day, the same week big sur got it's official release, catalina just runs noticeably hotter, fan is constantly running, and I can't help but feel its the sort of fishy thing apple have been called out on previously.
 

osxinu

macrumors newbie
Nov 4, 2012
14
2
I have an intermittent problem on my 2015 15 pro where the GPU draws maximum current at idle and therefore the temps go up. Have to shutdown and then reset PRAM on startup to reset the GPU load. Sometimes I have to do this several times.
 

Brandon Miles

macrumors newbie
Original poster
Jun 20, 2020
18
1
I have an intermittent problem on my 2015 15 pro where the GPU draws maximum current at idle and therefore the temps go up. Have to shutdown and then reset PRAM on startup to reset the GPU load. Sometimes I have to do this several times.
Resetting pram and smc is a good idea, cheers! As for your issue I'm sorry that sounds painful to deal with and probably impossible to fix without a new logicboard
 

juan985_Spain

macrumors member
Jun 30, 2019
67
30
I have an intermittent problem on my 2015 15 pro where the GPU draws maximum current at idle and therefore the temps go up. Have to shutdown and then reset PRAM on startup to reset the GPU load. Sometimes I have to do this several times.

¿Do you have the integrated intel iris pro 5200 or the dual graphics AMD discrete graphics?
 

osxinu

macrumors newbie
Nov 4, 2012
14
2
Resetting pram and smc is a good idea, cheers! As for your issue I'm sorry that sounds painful to deal with and probably impossible to fix without a new logicboard
Thankfully this only occurs on restarts. So I cringe every time I update. Interestingly, the Big Sur upgrade went without a problem.
 

Tankmaze

macrumors 68000
Mar 7, 2012
1,694
336
I have the 2015 15" MBP with AMD and still runs Catalina.

it doesn't run hot when Big Sur released, I also have change the thermal paste 6 months ago and it seems to run fine, I have attached my temp screenshot with safari and chrome running.
 

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Yebubbleman

macrumors 601
May 20, 2010
4,530
1,295
Los Angeles, CA
Since Big Sur has be released my macbook runs 20°C hotter than usual. I use SMCFan control to measure temps and instead of sitting at 40°C idle its running at 60°C idle and on loads at 80°C instead of 50-60°C.

I haven't updated to Big Sur, I haven't downloaded Big Sur and have been using my mac the same amount before and after its release with concistient results.

I'm no conspiracy theroiest but since apple has been caught out before with intentially slowing down older machines especially iPhones I am curious to see if anyone has a similar issue or if anyone knows what might be causing issues for myself.

Cheers.
Have you replaced the thermal paste on it?

If you're going to use any laptop (or desktop, for that matter) longer than five years, I'd recommend it. It will definitely give the thermal operation on your Mac a new lease on life. As for what could cause fan temps to ramp up more a year after, perhaps the internal process that checks for updates is tripping out because it sees that Big Sur is available and that you're not moving to it?
 
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