04-11-2015 08:51 AM
Dear Lenovo developers,
the T440p itself was already a kick in the teeth for customers that expect well-constructed machines for a suitable amount of money. I just like to mention the faulty power supplies (fixed by replacement), faulty system boards after installing Linux (fixed with new BIOS release and replacement of the death T440p), the flickering Problem of the VMM2322 Video-Hub in the docks (firmware update available but even with up to date drivers sometimes not a completely fixed problem).
It is well known, that the design of the T440p cooling system is used to its capacity – and sometimes not sufficient – to keep the quad-core i7 models from throttling (in our case the i7-4800MQ) when the CPU load is high over a longer amount of time (e.g. video rendering) and ambient temperatures are high or the sun is shining on the machine. But a design flaw of the ThinkPad Ultra Dock makes it even worse!
The part of the Dock with the power and eject buttons seals of half of the venting outputs of the T440p cooling system. The T440p is equipped with three ventilation grids on the back and five to the left side. From the five ventilation grids on the left side four are blocked up by the Ultra Dock. I am aware, that inside the dock there is a very small air-passage, but this is blocked by two fences at the inlet, the mechanics inside the dock a fly-screen like construction and again two fences at the outlet. It is obvious, that there will be no air-flow going through this construction. So the air can only escape through the gap between the T440p and the dock of about 1 to 2 mm. But half of that air is vented underneath the T440p and get sucked in through the intake again... A perfect vicious circle!
Result of this design flaw: The CPU of the T440p is throttling all the time when the machine is used for CPU based work docked on the ThinkPad Ultra Dock. And this is not a problem of one machine. I own two T440p and other users of the german thinkpad-forum have the same issue – some build their own workaround but I hope that this report gets forwarded to the Lenovo consulting engineers to solve this problem in further generation of ThinkPad Docks.
04-28-2015 03:16 PM
This is not a new design flaw unfortunately. My T410 has the exact same issue. Instead of only 4 of 5 vents blocked, all of the side vents are blocked.
The vents on the T440(s)/450(s) have been moved away from the corner, so the vents are no longer blocked. Unfortunately, those models only support 15W TDP processors, so they don't really have to worry about heat anyway.
Lenovo can keep the dock design, just flip the cooling system to vent out the other side. Some of the 15" models are set up this way.
07-22-2015 06:05 AM
Thanks so much for writing this. I have the T440p with an i5 CPU and only Intel graphics. When doing some video rendering the CPU temp shoots up to 95C-96C right away (while docked) and the fan is at max over 4400 RPM's.
It's a real head-scratcher how Lenovo could have made such a mess out of something like this!!
I just got another T440p with dock for another employee and it's got the i7-4810MQ and I am kinda hoping it doesn't go up in smoke (literally) ...