Become a MacRumors Supporter for $25/year with no ads, private forums, and more!

'18 or '19 MBP: clamshell mode?

jimtron

macrumors member
Original poster
Jul 27, 2008
87
4
I currently have a 2015 MBP, I use it mainly at home in clamshell mode (closed, vertical in a stand), with external display. I'll likely be buying a 2018 or 2019 MBP soon, and wondering if anyone has experience with either of these in clamshell mode; want to be sure there's no issues with that.
 

subjonas

macrumors 68030
Feb 10, 2014
2,862
2,578
Is there any difference between regular and clamshell mode in regards to performance/heat when under heavy load, and wear and tear over time?
 
Comment

smirking

macrumors 68030
Aug 31, 2003
2,626
2,291
Silicon Valley
Is there any difference between regular and clamshell mode in regards to performance/heat when under heavy load, and wear and tear over time?

Just don't leave it lying flat on a table. Mount it in a stand of some sort to allow for better ventilation. Someone started a thread around here a while back where he noticed that his MBP ran around 10% or so hotter on a consistent basis when he had it in clamshell mode and sitting flush on a desk.

I use mine in clamshell mode all the time. I've used all of my MBPs going back to 2010 in clamshell mode and all of those survived ok. I transitioned from being a Mac Pro desktop user to a laptop user and to this day my laptops are still used like a desktop when I'm not on the go.
 
  • Like
Reactions: subjonas
Comment

x-evil-x

macrumors 601
Jul 13, 2008
4,911
2,671
Just don't leave it lying flat on a table. Mount it in a stand of some sort to allow for better ventilation. Someone started a thread around here a while back where he noticed that his MBP ran around 10% or so hotter on a consistent basis when he had it in clamshell mode and sitting flush on a desk.

I use mine in clamshell mode all the time. I've used all of my MBPs going back to 2010 in clamshell mode and all of those survived ok. I transitioned from being a Mac Pro desktop user to a laptop user and to this day my laptops are still used like a desktop when I'm not on the go.
Ventilation will be no different turned. The vents are in the sides and if you open the lid you’ll get better cooking. It’s just the way it is. I keep mine slightly opened because of this. I’d rather have less heat over the life of the computer than more. So I leave it cracked.
 
Comment

smirking

macrumors 68030
Aug 31, 2003
2,626
2,291
Silicon Valley
Ventilation will be no different turned. The vents are in the sides and if you open the lid you’ll get better cooking. It’s just the way it is. I keep mine slightly opened because of this. I’d rather have less heat over the life of the computer than more. So I leave it cracked.

I don't doubt that's true, but it's still going to run hotter with an entire side insulated by a a material with poor heat conduction qualities than when fully exposed.
 
Comment

x-evil-x

macrumors 601
Jul 13, 2008
4,911
2,671
I don't doubt that's true, but it's still going to run hotter with an entire side impeded by a a material with poor heat conduction qualities than when fully exposed.
What do you mean entire side? There’s vents on both undersides aiming out so the vents aren’t blocked while sitting on a table. Slightly open adds more venting through the back opening by the kid and heat to dissipate better.
i don’t see how temperature would be better on its side compared to on a table both being closed. It’s not like on a table it blocks the venting.
 
Comment

x-evil-x

macrumors 601
Jul 13, 2008
4,911
2,671
I mean that the table may not block the vents, but it still acts as an insulating surface against the exterior shell of the laptop to impede additional heat loss that could happen through radiation into the air.
negligible :p
 
Comment

Weaselboy

Moderator
Staff member
Jan 23, 2005
30,894
10,665
California
I currently have a 2015 MBP, I use it mainly at home in clamshell mode (closed, vertical in a stand), with external display. I'll likely be buying a 2018 or 2019 MBP soon, and wondering if anyone has experience with either of these in clamshell mode; want to be sure there's no issues with that.
I run a 2018 13" MBP in clamshell full time and it works perfectly. Before that I ran a 2016 and had no issues.
 
Comment

Crossbow.Wallaby

macrumors member
Feb 2, 2017
41
10
Sydney, Australia
2018 15" MBP run it in clamshell mode often, for days at a time, sometimes standing flat sometimes vertical in a mount. Have not noticed any issues. I can check the temps in Macs fan control and compare in each mode if it helps you out? Not sure how much of an accurate reflection that gives though.
 
Comment

smirking

macrumors 68030
Aug 31, 2003
2,626
2,291
Silicon Valley
Well, I just tried an experiment. I exported 1000 RAW photos from Capture One Pro and had a watermark added onto them. I exported them with my 2018 MBP in the following modes:
  • clamshell vertical with vents on bottom (minimally obstructed by stand)
  • clamshell vertical with vents on top
  • clamshell flat on desk
  • clamshell flat on desk with lid slightly cracked
I ran the export and once the fans kicked on strong, I started changing positions with my MBP. My expectation would be that if any one mode had a heat penalty, I'd see the package temperature start bumping up, but I basically saw nothing conclusive. If any of the modes were better for heat than others, it was only better by 1 degree Celsius. Once the temperature stabilized, it ran at around 78 degrees +/- 2 degrees Celsius no matter how I oriented my 2018 MBP. It mostly stayed within 1 degree of 78.

Now it could be that the fans were working slightly harder in one mode than another and I couldn't tell the difference. That's totally possible, but that would mean that the fans were working well in all modes and any real difference would have been hard to distinguish... at least for this particular scenario. My job stressed the GPU much harder than the CPU. Maybe results would be different if someone pushed all 8 CPU cores for 10 minutes instead.
 
Last edited:
Comment
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.