Why is my 2.6Ghz 2018 MBP running so much hotter than the 2018 2.2Ghz model?

mossme89

macrumors 6502a
Original poster
Jul 2, 2009
539
96
Picked up a new 2018 2.2Ghz MacBook Pro while my 2015 model is being fixed. Love it and will end up selling the 2015 model. But I did want 500GB of storage. 256GB is too little. So I ordered a refurb model from Apple. It's a 2018 model but with more storage. And I will be returning the 2.2Ghz model.

Here are the specs of the 2 machines:

New 2018 15" 2.2Ghz i7 MBP. 256GB SSD. 16GB RAM. 555X GPU.

Refurb 2018 15" 2.6Ghz i7 MBP. 500 SSD. 16GB RAM. 560X GPU.

I'm noticing that the 2.6 refurb is running SIGNIFICANTLY hotter than the new model while doing the same things. The 2.2Ghz new model is running around 36C while the 2.6 is at 70C. I'm typing this on the 2.2Ghz model.

Why is the 2.6Ghz model running so much hotter? Thermal paste issue? That's my theory. Any advice on how to resolve that? I would just do it myself but I don't want to damage something or void my warranty. But if I take it to the Apple Store I know they will do their diagnostic bullcrap, have me format the machine when I'm 99% sure this is a hardware thing.

Oh and yes, I have made sure to make the comparison identical.

  1. I've enabled SMCfancontrol on both and set the fans to max on both
  2. I've also enabled Volta and set them to the same settings - no undervolting, turbo boost enabled
  3. I've turned them off for 30 minutes and then turned them back on.
  4. Both just have FireFox up.
  5. They are using the same Time Machine image. So they are equivalent for all intents and purposes.
 

Eason85

macrumors regular
Jan 29, 2017
233
282
Hong Kong
Did you check cpu utilization % and see if there's a rogue app running? Only other reason is bad paste job or bent CPU heat spreader
 

Toutou

macrumors 6502a
Jan 6, 2015
699
945
Prague, Czech Republic
Idling at 70 °C with the fan at full RPM sounds very broken. I can't imagine the temps climbing that high even with no thermal paste at all. Maybe the temp sensor is shot? I'd suggest going through their diagnostic bullcrap and having them sort it out.
 

leman

macrumors G4
Oct 14, 2008
10,236
4,732
There is no reason why it should. As Eason85 already said, watch your Activity Monitor for abnormalities. Most likely you have a process there requesting a lot of CPU uptime.
 

maflynn

Moderator
Staff member
May 3, 2009
64,182
30,758
Boston
I'm noticing that the 2.6 refurb is running SIGNIFICANTLY hotter
Because the thermal design of the MBP is inadequate for these hot running CPUs and so the 2.2 is running cooler and able to not throttle as much. I had a 2.2 (it's been sold) and my benchmarks were better than the 2.6 and even the i9 variant.

My opinion is that these machines just plain old run hotter.
 
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lJoSquaredl

macrumors 6502
Mar 26, 2012
290
72
Because the thermal design of the MBP is inadequate for these hot running CPUs and so the 2.2 is running cooler and able to not throttle as much. I had a 2.2 (it's been sold) and my benchmarks were better than the 2.6 and even the i9 variant.

My opinion is that these machines just plain old run hotter.
So 2.2ghz baseline for the 6 core or don't even bother upgrading?
 

mossme89

macrumors 6502a
Original poster
Jul 2, 2009
539
96
Is it possible my computer needed to be "broken in"? After further usage.... the issue has gone away.
 

1050792

macrumors Demi-God
Oct 2, 2016
2,545
3,933
Broken in is for speakers not for laptops. My i7 2.6 runs around the same temperature as yours, the CPU is more powerful hence why it's producing more heat. Don't worry it won't break.
 

maflynn

Moderator
Staff member
May 3, 2009
64,182
30,758
Boston
Is it possible my computer needed to be "broken in"? After further usage.... the issue has gone away.
No, Apple messed up imo, in putting such hot running processors in the same enclosure from prior years. These coffee lake processors run hot, and many other are incurring thermal throttling as well. I'm looking at you Dell.

The chassis was designed to run on a cooler quad core processor (or dual core for 13") and now we have hex cores running a lot hotter then prior generations. I like what Razer has done with its 15" laptop. The latest RTX version is crushing games with the RTX 2070 GPU, 8750H and having temps in the 80c range. Their vapor chamber cooling is fantastic.

I think one major reason why we're seeing rumors of a 16" laptop from apple is simply because the thermals, apple designed themselves into a corner with a too thin laptop. I agree with Dave2D's reasoning.
 
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Conutz

macrumors regular
Oct 24, 2014
205
113
Joburg
Is it possible my computer needed to be "broken in"? After further usage.... the issue has gone away.
As other posters said, it was likely a process requiring CPU resources. Also, since it’s newly set up, it was probably Spotlight indexing the drive.

No, Apple messed up imo, in putting such hot running processors in the same enclosure from prior years. These coffee lake processors run hot, and many other are incurring thermal throttling as well. I'm looking at you Dell.

The chassis was designed to run on a cooler quad core processor (or dual core for 13") and now we have hex cores running a lot hotter then prior generations.
I think this has been a tough one for Apple - they committed to a design around 3 years ago and they’re using another company’s product within it. That Intel continued to battle with their processes probably wasn’t anticipated (look at Apple’s Axx progress and performance and at Intel’s promises). To carry out a full re-design late on is probably next to impossible, so Apple was likely bound to a large degree. There are of course some options for improved cooling, but they would always be somewhat limited by the design. Talk about a rock and a hard place.

This whole reliance, and this occurrence specifically, are probably big motivators for a migration to ARM.
 

Queen6

macrumors 604
The higher clocked CPU will pull significantly more Watts resulting in higher operating temperature, as the relationship is not linear. A background process may well tip the balance, resulting in a hot and noisy notebook.

Apple's cooling solution is woefully inadequate being literally the same as the old quad core CPU's, therefore no surprises that the current notebooks are not capable of levering the addition performance the 8th Gen CPU's offer. Unless Apple dramatically rethinks the upcoming 9th Gen Octa Core CPU's will be an even bigger disappointment/embarrassment.

Q-6
 

mrt.plt

macrumors member
Oct 22, 2015
71
37
Montreal, Canada
As other posters said, it was likely a process requiring CPU resources. Also, since it’s newly set up, it was probably Spotlight indexing the drive.
Apple should add a warning message about this at the first boot! Especially when you first set a Mac up fans keep spinning hard for a while, worrying users.
I have a 2018 2.6 i7 and it idles around 40-50 degrees, and fans spin much rarer compared to my 2015 15".
 

jakespeed

macrumors member
Jul 22, 2002
77
27
Make sure you do a PRAM and SMC Reset before you return the 2.6. My 2.2 was running hot (50-60c), getting terrible battery life and crazy spinning fans. The standard resets brought it down to about what you are seeing. I was VERY close to returning it and the difference was night and day. Now I get nice cool temps and a solid 10-12 hours of use web surfing 6ish working in Parallels. I went from unhappy to very happy and ended up keeping this 2.2 and love it.

Also note that the hot keys have changes for SMC for the 2018's...seems you use the right shift key instead of left (again if memory serves me.)

Jake
 

Conutz

macrumors regular
Oct 24, 2014
205
113
Joburg
Apple should add a warning message about this at the first boot! Especially when you first set a Mac up fans keep spinning hard for a while, worrying users.
I have a 2018 2.6 i7 and it idles around 40-50 degrees, and fans spin much rarer compared to my 2015 15".
That’s not a bad idea! It’s funny how relative it can be though. The other day I set up a new Dell desktop with an 8th gen. i5 and a 1TB platter (can’t remember exact specs). I let it do all the Windows updates, etc., but it would just not. stop. grinding. away. It felt like an absolute eternity before the things was actually usable so I could install the software that was required.

When I’m lucky enough to upgrade my MPB, I do the restore and then just let it run on its own for a little while it does the housekeeping...and I enjoy the new smell in my office :) During that time, fans can rev away, I know what it’s up to. I travelled shortly after getting my base model 2018 with 32GB and 1TB and while sitting in the airport lounge was amazed at the predicted life I was getting - somewhere around 12 hours, or more. Loved it then and love it now.
 

mrt.plt

macrumors member
Oct 22, 2015
71
37
Montreal, Canada
That’s not a bad idea! It’s funny how relative it can be though. The other day I set up a new Dell desktop with an 8th gen. i5 and a 1TB platter (can’t remember exact specs). I let it do all the Windows updates, etc., but it would just not. stop. grinding. away. It felt like an absolute eternity before the things was actually usable so I could install the software that was required.

When I’m lucky enough to upgrade my MPB, I do the restore and then just let it run on its own for a little while it does the housekeeping...and I enjoy the new smell in my office :) During that time, fans can rev away, I know what it’s up to. I travelled shortly after getting my base model 2018 with 32GB and 1TB and while sitting in the airport lounge was amazed at the predicted life I was getting - somewhere around 12 hours, or more. Loved it then and love it now.
I totally agree. I know it's gonna do some indexing and whatnot for the first hour or so, so I just do some light work on it (or not, if I still have the MacBook I'm upgrading from) and enjoy the smell.
Honestly I'm in class right now, just following slides and taking notes on OneNote, my battery's at 94% and it gives me an estimate of 9 hours and 59 minutes, and the best part is I know it'll last this long under these conditions. It's funny, the only reason why I carry its charger around is to charge my Surface Go.
 
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