Mid-2014 15" MacBook Pro Retina Thermal Issues

[MZ3Alex]

Hello all, as the title suggests I'm having some thermal issues with my MacBook Pro that have me very puzzled. I started noticing a few months ago it was getting very hot even under relatively minimal loads. What I was seeing was even with a ~25% load from basic Safari web browsing and Youtube, temps would start spiking up to 85C. Now the weird thing is at idle the temps sit acceptably low for a MacBook: high 40s / low 50s (I'm at work right now and it's sitting here idling at 44C). At around ~45% load playing a game on Windows with an eGPU, the temp goes straight up to high 90s (confirmed with Afterburner) and fans ramp up to max. So why then would such a small increase in workload send the CPU temp so high? I don't recall it having done this during the first few years I owned it. Even when the fans ramp up under this load, it does very little to bring down the temperature.

So far I have tried several things:

• Verified no rogue processes hogging CPU.
• Complete internal cleaning of dust and debris (wan't much to begin with).
• Redid thermal paste: first with Arctic MX-4 and then Arctic Silver 5 to see if any difference (not really).

The only thing I can think of at this point is the heat pipe has somehow gone bad. Maybe the liquid inside leaked somehow? I did find some oily substance on the top of the pipe at each side where the rubber seals are that I presume are helping to seal the airflow out/into the back of the machine. What I can't tell though is if the substance was from the adhesive that helps to stick the rubber seal to the heat pipe as it seems like that's also plausible.

So any thoughts or ideas?
Help is much appreciated!

 

[leman]

Maybe it could have something to do with how CPU usage is reported? Your CPU has 8 logical cores, so 100% use means that all these cores are loaded up with work all the time. 25% could mean either 8 logical cores loaded up 25% of the time (unlikely, since OS doesn't like to do it), or it could mean 2 cores being loaded 100% of the time. And in the later situation your CPU would boost and use a lot of power, so high temperatures are expected. Same goes for the 45% CPU utilisation (its more like 4 cores being loaded all the time). Temperatures you are observing are normal under high load.

To verify that this is what you are seeing, I'd recommend using Intel Power Gadget or an alternative tool — you are interested in CPU power consumption. If it reaches these high temperatures while consuming under 15W of power, something is wrong. My prediction that you will see 30W and up to 50W power use though.

 

[MZ3Alex]

Thanks for the info @leman! I ran a test tonight where I let a Youtube video run in Safari with no other windows open. As seen in the IPG graphs below the temperature averages about 78C. While I didn't get a very noticeable fan ramp-up like I have before, frankly I still think this is too high considering the <20% average utilization. Ambient temperature in the room was 21C. Graph I believe is about 2-3 min of data @ 1 second intervals. Also this machine has the i7-4870HQ i7-4980HQ processor w/ i+dGPU.

Regarding power consumption, it's at the lower end of what you mentioned. Disregard the spikes at the end as this was me opening up Screenshot. I think it would be fair to say I expect the temperature to average out ~10C lower in this case, or would that not be reasonable?

 

[leman]

@MZ3Alex I'd say that your screenshot clearly shows high single-threaded CPU utilisation. The CPU power draw is 25-30Watt and the CPU is also boosting. I don't think that there is anything wrong with your machine to be honest. Could you run Cinebench to check whether your scores are within the expected range (just to verify that the performance is fine)?

It's another question altogether why you get high CPU utilisation with Youtube to begin with. Looks like your CPU is decoding the video in software, which is a bit odd. The 2014 MBP should do hardware decoding if I remember correctly, but I don't have that kind of machine at hand to check for myself...

 

[MZ3Alex]

@leman Firstly I have to apologize as I was a bit under the weather yesterday and I mentioned the totally incorrect CPU above. 🤦‍♂️ It's actually the 2.8Ghz i7-4980HQ. So with that out of the way....

I ran both Cinebench R15 and R20 with these results:
R15 -> 547 pts.
R20 -> 1346 pts.

It's hard to tell if these are expected or not since I couldn't find a database to compare them to and Google doesn't reveal much. I only found this website which gave an R15 score of 696, but who knows how they tested that or if it was from a MBP.

Regarding single-threaded CPU usage, you're 100% right. That's exactly what it's doing as confirmed with activity monitor. About Safari hw acceleration, it's an interesting point. Do you know how I could tell for sure if it's actually utilizing it? I can't seem to find an indicator for this anywhere besides just watching the utilization graph but that doesn't tell me if it's actually hw acceleration or just increased GPU utilization due to video playback. This particular model is also difficult because it's one of the last produced with the Nvidia dGPU before Apple gave them the middle finger and went AMD. (Though starting with 10.14 they've also given the middle finger to their customers too with no further Nvidia driver support.) How or even if Safari hw acceleration is still possible on 10.15 with this machine I'm not sure. I think WebGL is out of the question now too (which I tested on YT but didn't really do anything noticeable).

Anyhow, back to topic though. If you're thinking the temps look okay then perhaps I'm just overreacting a little. I'll still keep an eye on it though and watch out for anything strange. Might be getting ready for an upgrade soon anyways with the new 16-inch models on the horizon and new scissor keyboards.