Just another one…
MBP 16", 2,3 GHz i9, 32 GM RAM, 1 TB, 5500M 4GB
LG 5K screen (1st edition, TB-only and 86 Watt via TB3)
- Clamshell: about 5 Watt on the Radeon.
- Would be even better with Intel-GPU (as an option), but I think this is fine, given the machine has external power and a GPU to use on a Hires display.
- 45°C to start with, 50° with light usage. (Just now. "Airflow" to just keep a singel value. Temperatur around connected TB3 port is higher, but CPU/GPU are okay.)
- Open lid: about 18 Watt on the Radeon.
- Idle temperature rises from 45° to 55° within a minute or two.
I noticed, because the machine definitely get "very warm to the touch", which an idle machine should not do (in my opinion).
- No external device: internal GPU; cold, good battery on playing video. (And with a rather big Retina display… that#s good.)
As I understand, it's a suspected driver optimization/setting/issue/… - since people report the jump not to happen on Win10 on the same machine. (Haven't tried that yet, since I was so far using Win10 only in VMs on my Macs. And there's funny quirks/changes when playing with resolution, refresh rate, and even rotation of screens.)
Apple hasn't acknowledged that; nobody knows, if this is fixable is possible in SW/firmware, or if it would be coming or not. As I understand, using the Intel GPU on external screen is inhibited by HW design.
Previous 15" models 5x0(X) could handle this better, as does the new 5600 option. (Which has HBM2 RAM, which may be more energy efficient; however, since we talk idle behavior here, it's assumed to be a driver setting issue; e.g. with RAM clock to improve performance. I read about this topic (RAM clock with more/"bigger" screens) in general also with standard PC PCIe cards, but trend the last years was to handle more and higher resolution displays with less Watts; see
previous generation of AMD cards in the 15" ones…)
Obviously improved TDP design (16" over 15") of the model is intended for high-power usage, to allow more Watts being turned into computation. That should not affect idle-power behavior. But cooling system isn't the issue here anyway.
The new "more efficient" GPU is hopefully not only more efficient at high power usage…
I understand, I have not hit the worst case (since clamshell mode is fine not going for high-power GPU.)
Hence using SwitchResX won't help me, since people could effect behavior with single/multiple external displays, but not in conjunction with the internal one?
Until I have some "heavy load" on the system, I'll monitor temperature; and only then will consider items like "Turbo Boost switcher".
Well then; I'll try the system the coming days (and if I can live with Clamshell most of the time). Otherwise I might opt for 14-day-return option hereabout.
Beyond, I shall consider contacting Apple about the "issue" and if I can come up with any other idea about what might help. (Yes, I know about eGPU and 5600 options; but that's making the system work "as intended" I just spend enough bucks on…)
Appreciate all the information/tips collected here. 👍