MacBook Pro 16 - long term high temp usage? (ZBrush)

[TimothyB]

Hi all,

Is there any danger to the laptop if it runs at 90-100c for some tasks, hours at a time? In this case, clamshell mode, standing vertically.

I’m a graphic designer, but my 3D modeling interest had me switch to PC years ago. Though, I always missed Mac OS and still use it daily for graphic design at work. The new 16inch seemed like a perfect time to dive back in.

What do I do that causes 90-100c temps? With the mention of 3D you might think rendering with 100% CPU, nope, I’m talking about ZBrush. This program doesn’t use GPU, but the CPU For mostly everything, so it seems to take all the power it can get at all times. This causes temps of 90-100c just after loading, moving the cursor. Even its built in artist screensaver will cause loud fans and high temps while the system idles.

So on an i9 with 16 threads (8 cores), you might think, drop it down to 8 threads in The performance settings, nope, still about 90-100c with fans. Even at 2-4 threads, you’ll see temps of 85-95. So strange to see the Intel Power Gadget showing such low CPU usage, but very high temps. Thing is, you need about 4 cores for smooth performance, especially when zooming a model past the viewport frame and rotating it. So dropping down to 1-2 cores and still seeing high temps is a bummer.

Please note this isn’t a problem with the machine, but an existing problem going back years between Pixologic and Apple with a lot of finger pointing. I had hoped this was solved.

I wish there was a way to throttle the CPU on Mac to control some of the heat while maintaining ideal performance in ZBrush.

Though, I can live with fan noise, and if the MacBook Pro is in no danger at these temps, it’s something I can live with.

Note that just running two external screens, clamshell, with 4K ultra wide and 4K Cintiq display, both off of USB-C, will see 60c idle temps. Running just one of them might lower the idle temps to 47-50c. Using a Wacom pen also causes the CPU to raise its frequency, even just hovering the pen, not something a regular mouse does.

 

[BigBoy2018]

1) The heat is normal, but ...
2) It will shorten the life of your laptop

One thing to consider is turbo boost switcher (https://www.rugarciap.com/turbo-boost-switcher-for-os-x) Its a nice little app that allows you to turn off turbo boost. Turbo Boost is effectively useless for anything other than really shorts bursts of speed (and making geekbench scores artifically higher). Turning off turbo boost won't cause you any speed loss for long hard workloads, but will result in cooler temps.

Also, having the laptop running hard in clamshell mode while on it's side is not ideal. It wasn't really designed for hard work in that position, imo. But again, as long as it's not causing the machine to shut down, it's within design tolerences. But it will shorten the life of your machine.

 

[casperes1996]

The issue with trying to manage utilisation through number of threads, is that modern chips will just increase frequency when fewer threads are loaded, which is less efficient, causing as high temps. The only benefit is that it allows you to load the remaining threads with other tasks.

 

[currahee2100]

Those temps are pretty bad. Can you do anything about it? Unfortunately no. My 2012 MBP gets that hot. Haven't measured my 2018 MBP while gaming which adds a large load. I have macs fan control set to blast the fan when it reaches 70C and it stays under. But if its that hot your fans should be going full blast anyway.

 

[leman]

Is there any danger to the laptop if it runs at 90-100c for some tasks, hours at a time? In this case, clamshell mode, standing vertically.

Short answer: no, there is no danger.

Long answer: every MacBook Pro I can recall was designed to run at hot internal temperatures under heavy load. This is Apple's way to maximise the available performance. These temperatures are absolutely safe for the hardware to operate at and hardware manufacturers give you full warranty even if you do so 24/7. While it is true operating at high temperatures will shorten the life of an electronic component, the timeframes we are talking about are completely irrelevant for any practical operation. Your computer will break down of other, unrelated issues, or will simply become obsolete and be replaced, long before any component deterioration due to high temperatures will become critical.

Bottomline: this laptop is a professional tool, designed for your use case. Don't worry about it and just use it to create some great stuff.

P.S. If this kind of operation is the standard case for you, it is also possible that a laptop might not have been a proper tool for the job. Desktop computers are still much more suitable for this kind of work.

 

[BigBoy2018]

P.S. If this kind of operation is the standard case for you, it is also possible that a laptop might not have been a proper tool for the job. Desktop computers are still much more suitable for this kind of work.

Agreed. This seems like the real take-home message. It sounds like you essentially use it as a ‘desktop’, so why not just get an imac, which offers better performance at less the price and has much much better thermals.

 

[TimothyB]

Thank you for everyone's input!

A desktop seems the optimal choice for 3D work, at least for times when you need to do heavy lifting. If only they had a Mac Pro tower that was similar to the iMac. Though, the MacBook Pro should handle most situations. Most ZBrush projects should be light work, it's just unfortunate it has this issue with MacBooks. As back-up, I still plan to keep my Gaming PC around (8700k, 32Gb, RTX 2080) for situations with high 100% CPU usage, like rendering.

BigBoy2018,
Thanks for the tip on the Turbo Boost Switcher. I purchased the Pro version and set it to disable turbo boost when ZBrush is in open.

Below are some, temp and power results. (Setup

1. Woke MackBook Pro from sleep all day (So started fresh)
2. MacBook Pro in clamshell mode, standing in Twelve South Bookarc. Running LG 38" Ultrawide (3840x1600) and 16" Cintiq (4k), both connected by USB-C. LG also providing 60 Watt power source.
3. Started with Turbo Boost Off, continuously rotated ZBrush viewport (normal work would have pauses), max 16 threads performance setting.
4. Switched Turbo Boost On, rotated viewport again.

Temps and power use were lower with Turbo Boost, and no loud fans. Seems perfect, as I just want to keep it under control while working in ZBrush, as it doesn't require that much horsepower all the time. As you see when I turn Turbo Boost on, power and temps spike quickly.

Screenshot from Intel Power Gadget:

 

[TimothyB]

While I’ve since returned the MacBook Pro for now. Has anyone tested the latest ZBrush release, 2020.1? Release notes have a very interested item:

• Fixed: Improved Mac fans issue on macOS

I’m curious what this means. Does the CPU spike less in ZBrush now, reducing temps, does it play better with lowering the core count without having to use just 2 cores, or is a the fan less erratic, but cpu usage and temps still the same?