DuhSesame

tht said:

DuhSesame said:
Like somehow still believes thicker really means cooler.

The macplusplus heat transfer conversation was really weird. First of all, cool that people are talking heat transfer! The crowd isn't going to hewn to an "all things being equal" rule, and everyone is talking about their own part of the heat transfer train.

Like in my other post, the 5th gen MBP (2021 models) models are not really thicker than the 4th gen models (late 2016 to early 2020 models). They only look thicker. The +0.5 mm thickness of the 2021 MBP16 won't effect the cooling performance much at all, effectively zero. So, for all intents and purposes the two generations are the same size imo, especially with respect to cooling. It's just that the industrial design of the 2021 models make them look thicker than 2016 to 2020 models. Therefore, one can not make any conclusions on cooling performance between the two machines based on their looks.

Convective heat transfer performance is driven by the difference in temperature between the heat source and ambient air, the heatsink (radiator fins) surface area, and the flow rate across the surface area. There is a heat path from the CPU & GPU that heats up the area on top of those chips, which is always the keyboard and the area by the hinge in the vast majority of laptops. The temperature of this area and the operational ceiling of the chips determines when the fans are ramped up (and the designer's choice). More mass here only increases the time for this area to heat up, but it will reach about the same equilibrium temperature as there is very little difference in the heat transfer from the keyboard area to the ambient air for virtually all laptops. The hotter the chips, the faster this area heats up and the hotter this area gets, the faster the fans have to ramp up to keep the chips and this area cool.

For more cooling performance from the fans, you can increase the flow rate across the heat sink (radiator fins), but this means either higher fan RPMs, which means more noise, or larger fans which means you need to increase the size of the device or decrease the size of the other components to make space for larger fans. You can also increase the heat sink surface area by adding more fins or having bigger fins, which means you decrease the size of other components or have a larger device. You can do a bit of both. I take it that using the device at 65 °F is not a viable consumer strategy (the server rack strategy).

So, yes, if you want more cooling, the easiest path is to have a larger device in which you can have bigger, higher RPMS fans, larger heat sinks (radiator fins). For thinner laptops, to get equivalent cooling performance, it means ever higher RPM fans as you are space limited, and that all translates to noise, and more often than not, having higher surface temperatures. It's a laptop, you have to touch it, and therefore puts a limit on how hot an OEM can let its surfaces get.

The huge win for the 2021 MBP is that the M1 Max and M1 Pro just use less power than prior the Intel + dGPU combo do, on order half to a third, and their idle power consumption also seems a lot less. If the CPU is only using 5 Watt on average, fans don't need to run. Intel on the other hand, could be at 10, 15, 20 W depending on model, on average. Double it when the dGPU is active. The fans have to run to keep the machine cool to the touch. Also, the M1 systems are more space efficient for logic boards, so Apple could put in a more performant cooling system, ie, larger heat sinks, larger fans. Bigger fans can also be quieter as they can drive the same flow rates at lower RPMs than smaller fans do. Bigger is better in basically all metrics for cooling performance.

Btw, if you look at the iFixit teardown, it looks like Apple put an insulator on the opposite side of the logic board from where the M1 Pro packages are. Was curious when of if an OEM would put an insulating layer beneath the keyboard to prevent the area from heating up. Maybe Apple is doing this with the MBP, but not sure. iFixit didn't take that part out. At some point, either Apple will have to have integrated vapor chambers or heat pipes on both sides of the package, or package+logic board. An insulator is an easy way to reduce temperatures of the keyboard. Also, wonder if being black also helps there. Not a lot, but perhaps some.

docno42 said:

DuhSesame said:
No other laptops (except Alienware) can do eGPU+external SSD without any interference. 

Apple SOC doesn't support eGPU and I would expect it's a low priority, if it's even a goal.  Another red herring.  

docno42 said:

DuhSesame said:

nor you’re adding much either, only two data and one special charging ports.

As for this - that special charging port is more than just a charging port; it's a safeguard against damage.  One of the biggest things I missed on the M1 MBA was magsafe!

And has already been discussed ad nauseam those other two data ports represent a HUGE increase in convenience and customer experience for those who need them.  I'm happy that you're in this magical bubble where you have no need for them.  You are far from the only user profile for these machines.  

docno42 said:

DuhSesame said:
My point stand, if I’d have to choose variety vs. bandwidth, I’d take latter.

But even with a fourth thunderbolt/usb you wouldn't be getting more bandwidth.  So your point is still pointless.