Feeling the heat
Laptop computers today pack more power than supercomputers of 30 years ago, with batteries that last at least three or more hours, in packages weighing less than 3kg. All of this is wonderful, except for one problem: the extreme temperatures reached on the surfaces in contact with your body (The new MacBooks / Pro from Apple don’t have any mention of being “laptops” anywhere). The temperature problem can be divided into three areas:
- Main processor / Video processor / Chipset (including RAM)
- Non-volatile storage (Hard disk / Flash memory)
- Battery / voltage converters
Modern CPUs boast a better ratio between wattage and computing power than CPUs from the past, but the increase in processing power has assured that the amount of electricity used has increased (and subsequently the amount of heat).
Hard disks have more capacity, and are faster every passing year, consequently producing more heat. Flash storage devices, which produce less heat, are still behind in terms of capacity, cost per MB, and read/write cycles compared to hard disks.
Finally, the batteries to power everything must have much higher capacities, and the increased chemical reactions generate even more heat, as the conversion and regulation, which also creates even more excess waste heat (although of the three it’s perhaps the part that is the least of our problems).
The possible solution (besides either saying that laptop computers are not “laptops”, or reducing their power, which are both not the solutions people are looking for) is a redesign in laptop architecture. The main area which is never in contact with the user’s body is the screen part. It would be ideal if most waste heat could be routed some way to the back of the screen. I can imagine three solutions, each with their own drawbacks:
- Move to the back of the screen the main and video processors, along with most of the chipset, and perhaps also the main fixed storage. The main drawback is in terms of balance – the screen part of the laptop computer should be as light as possible as compared to the “main” body. With the miniaturization of motherboards and CPUs, and with the possible switch to flash memory fixed storage this should be feasible. More space could be used in the main body for batteries, perhaps, for longer autonomy and to offset the weight.
- Use of a liquid cooling system, as available for desktop computers. Easier to implement than solution #1, but not very elegant on a laptop. There would be problems with routing the liquid tubing from the main body to the screen part, and it would also increase the overall weight of the system.
- Using peltier junctions to transfer heat from the end of the main body chassis to the botton of the screen lid. Mechanically difficult to implement, and it would also increase the power usage of the whole system a lot. Probably the worst of these solutions, even if theoretically more elegant in terms of engineering.
These are just a few ideas, I would like to know your opinion on this problem.
Bruno,
I understand your point of view, but if you had the whole computer behind the screen (except for the keyboard/touchpad/batteries/energy management), the number of connections would be even simpler than the current ones. You’d need only one USB pathway for the input devices, and separate lines for several voltages (unless you had the power conversion hardware also behind the screen). Nowadays, you need to have a voltage line to power the screen, the digital video connection to the LCD, wi-fi antenna cable, and in some cases cables for the microphone and integrated camera.
Have you read this article. Pretty old news though.
http://www.sciencedaily.com/releases/2004/03/040331004036.htm
Apart from that, what I hear is liquid cooling is not very safe, also much more suited to a desktop. Read a modding article where they submerged the whole computer in cooking oil! No fans obviously. It works, but imagine the trouble you would have to go through to replace a component!!
I am not an expert, but I think there might be some drawbacks on transferring more components (and heat) to the back of the LCD screen, as these are the kind of components that are extremely sensible to heat.
I also sense some problems here also, as you’d have to have some efficient way to route the gazillion connections from these components to whatever would be placed on the “bottom” of the laptop. Mine’s got two hinges (fragile enough) and a connector which I estimate to have a dozen tiny wires – power included) and it feels bulky… During the past few years, I had to change cracked LCD screens (or LCDs with broken hinges) on my laptops for a couple of times. I consider it an easy task. The helpdesk crew just takes them apart and replaces for a new one. Imagine if they had a CPU and a Graphcard inside…