MacBook Pro 15" 2017 - x265 video encoding in clamshell mode - **temperatures**?

[Jim Lahey]

Hello. I have a 2017 MacBook Pro 15" (2.9Ghz i7) and I need to run it for extended hours at very high CPU load in clamshell mode. It sits vertically in a Twelve South BookArc with the rear vents facing down. My question is - is this likely to soak too much heat into the keyboard, screen and battery? Battery temp according to Coconut Battery was showing as 37c after only a few minutes of x265 video encoding. At which point would you abandon ship? Or is the machine designed to operate in such a way for several hours at these loads without issue?

Thanks for reading. All opinions and advice welcome.

 

[adib]

The machine isn’t designed to operate this way for an extended amount of time. At best, prepare yourself for the display to have acne-holes due to its surface partially melting thanks to heat. At worst, the discrete GPU would overheat.

 

[Jim Lahey]

The machine isn’t designed to operate this way for an extended amount of time. At best, prepare yourself for the display to have acne-holes due to its surface partially melting thanks to heat. At worst, the discrete GPU would overheat.

I figured as much. Think I’ll abort for now then and do these tasks at another time. Thanks 👍

 

[GumaRodak]

Well, you can disable turbo boost or use application appolice and set cpu limit for the coding app. I use this when i want to recode sitcoms to mp4 or so… i let it run overnight and i can control the heat generation by cpu in this way…when i sleep i dont care that the machine is slowly coding

 

[mzeb]

The machine isn’t designed to operate this way for an extended amount of time. At best, prepare yourself for the display to have acne-holes due to its surface partially melting thanks to heat. At worst, the discrete GPU would overheat.

This isn't entirely clear. The machine is meant to continue to function in clamshell mode continuously and should just throttle down the CPU and GPU automatically if thermals dictate it. The machine will not damage itself being used in this way but it might get really sluggish for a time. It *shouldn't* happen but if it were to get too hot it would shut off before damaging itself.

Since you have a 2017 MBP have you considered an eGPU enclosure? OpenCL should offload to the external GPU instead of the internal one which would decrease the heat in the actual MBP case. You'd likely get better performance this way because you'd be using a desktop class GPU. If its in your budget this might be worth it.

 

[IceStormNG]

The machine will thermal throttle due to VRM overheating anyway after some minutes and puts out less heat.

You can take a fan or a laptop cooler pad to keep the exterior a bit cooler. I don't have the same machine, but the 16" with i9 which is also a space heater. And it work fine in clamshell mode. Even after hours of continous full load. You might want to force the fans to full blast with a tool like MacFanControl. The machine will throttle before anything gets to hot.
I also have a thin microfiber cloth between the keyboard and the screen. Not against the heat, but the keyboard slightly touches the screen normally. So you have keycap prints on the screen.

and BTW: Clamshell mode is supported and I haven't seen Apple warning people from using it. So it should be fine.

 

[Christopher Kim]

While it should throttle before causing any real damage, if it were me, I might not even want to risk it.

Maybe consider when doing these encodes (especially if it's just a few jobs you need to do, vs being an on-going/regular thing), take it out of closed clamshell mode. And just "use it like a laptop", while plugged in, during the encodes?

 

[Jim Lahey]

I am just not going to do these sorts of tasks in clamshell mode. I'm a bit anal about keeping my batteries in good health and so I don't think it's a great idea to let so much heat build up. While it may not damage the machine necessarily, I feel it's not going to do it much good.

Thanks for all your help, folks. Much appreciated 👍