As geeky as this may be, it's worth a read if you're ever thinking about buying a laptop and wondering if you should by that cheap one on sale...
For Father's Day 2011, I tore down and rebuilt my dad's laptop computer slightly better than it was before.
And in the process, I learned a lot about laptop mis-design:
* Just because you use the same ingredients as Thomas Keller, doesn't mean your cooking tastes like it came from a master chef.
* You get what you pay for.
First, a little back story.
Many many years ago, my Dad's laptop got stolen from his apartment in Taiwan. It was quite a feat considering the front door was untouched and the window open.
We're under the impression that the thief rappelled down the side of the apartment, and stole the laptop through Dad's 7th floor window.
Anyhow, so I got my Dad a business-class HP laptop (zt1135), and it worked for about 5 years until the display system started breaking down. Pretty good stuff.
So for Father's Day 2008, I bought my dad a Lenovo Thinkpad R61e.
Slightly cheaper than the average Thinkpad and a heavier model, but designed to be reliable and twice as fast as the old HP. Another low-cost business-class laptop.
It only lasted a year before needing repair because during that Taiwan typhoon season, it was humid enough condense a puddle inside the laptop, shorting out the DDR2 memory power supply.
Lenovo repaired it for free, but it wasn't going to arrive before Dad needed to fly back to Taiwan.
So he checked out some newspaper ads and bought a Compaq CQ50 from Office Depot because it was on sale and cheap.
The Compaq CQ50 is a consumer laptop that cost my dad about $450 after tax, and is equipped with a pretty nice 15 inch screen, and a 2Ghz dual-core AMD processor.
I stared at it for a short while wondering how come it's so cheap, and then promptly loaded his documents on.
So, where am I going with this?
Well, the expensive business-class laptops my Dad had worked pretty well and were fairly durable. (except for the typhoon incident) And I've heard great things about Thinkpads in general.
Likewise, all my personal Apple Powerbooks lasted a long time as well. All these were relatively expensive but well-built machines, based on how long they've lasted.
And now my Dad has a "consumer-class" Compaq for roughly 1/3 the price of the past laptops. Saving $1000 is a pretty big deal, but what are you giving up? Quality, apparently.
A month ago, my Mom came back from Taiwan with Dad's Compaq. It showed up:
1) with a broken screen. (dropped)
2) with an overheating problem: It starts out around 70C and eventually hits around 110C before it powers itself off to stave off meltdown.
3) with a bunch of malware pretending to be Windows XP repair utilities asking you for money.
#1 and #3 are kinda a given. If you drop the laptop, it's not going to be happy. If you run Windows, you're going to get infected. It's a given. It's expected.
But #2 was a unique problem. If your laptop can boil water... then.. uh, somebody screwed up. (By the way, a more normal range is 50C-80C.)
I looked online for some info and found others had the same problem. I also found a guide to help disassemble the whole thing without cracking pieces off.
The heatsink was covered in lint. A nice thick layer pulled off just like on your clothes dryer after drying 10 loads of laundry. The intake itself was covered in dust too.
After cleaning those out, I noticed the thermal paste melted and pretty much boiled off over the CPU.
So I fixed that up too.
And here's where things get creative. Inspired by another guy's youtube video, I cut a small heatsink using some bolt cutters and glued that onto the heat pipe between the CPU and GPU.
Then I used some graph paper for alignment and drilled a bunch of holes in the case right where that heatsink appears.
I know the heatsink isn't going to have much airflow over it, but it should keep things just a bit more cooler as long as any airflow happens.
Pictures at http://www.facebook.com/media/set/?set=a.10100579056303333.2896498.1229643
Powered it on, then ordered a used screen off ebay for $85, and installed that.
Operating temperatures now are between 55C-89C.
Ta-da! All good... for now.
So, on a lot of nerd message boards, there's always somebody who complains that "there's no way a Macbook Pro should cost $1800 when a Dell costs $500 especially cuz it's all the same Intel parts."
And while he's right that most of the parts that actually do computation are all roughly the same parts from the same vendors, there's certainly more to a laptop than a box of parts.
Let's do a compare and contrast, eh?
I'm most familiar with a 2008 Apple Macbook Pro 15" since that's what I'm using at the moment. And from the specification list point of view, fairly similar to the Compaq CQ50.
The two laptops are about the same size, and the Macbook Pro is slightly faster. My Macbook Pro's temperatures are typically 55C, peaking at 71C.
The problem we have here is that after a year's worth of use, the Compaq is hot enough to trigger its safeties, and the Macbook works just as it did new.
Why? Design.
The Compaq is made mostly of a plastic shell with a steel plate in the center to give the keyboard and logic boards some rigidity.
It's cheap and easy to manufacture, since you just need to mold it. Aside from enclosing the laptop, the plastic shell doesn't do much else.
The Macbook is made mostly of aluminum. It's expensive to make, but unlike plastic, it can act as both structure as well as heatsink. In order to support the actual heatsink and pipes, they're screwed into the shell, which means heat is carried and spread out through the shell as well. A significant win for removing heat.
Because the frame is sturdy already, the steel plate is unnecessary. This makes the keyboard area thinner too. When it's slightly perforated, hot air can escape on its own through the keys, improving heat dissipation once again.
The Compaq uses 1 fan which draws its air from a 1.5"x1.5" intake on the bottom of the laptop, and exhausts it from a 3 inch hole in the back.
The Macbook uses 2 fans on opposite ends of the laptop, which draws air from the back and pushes air out the back.
Not only does having 2 fans means more air can be moved, it can be done so with slower fans, making it more quiet than the Compaq. But that's not the biggest difference in design.
What makes the Compaq design so much worse is that the intake is on the bottom of the laptop. It's like a vacuum cleaner sucking up all the dust and lint from every desk you set it on.
Drawing air from the side of a laptop instead of the bottom means cleaner air. Cleaner air is less work for the fans, and cleaner heatsink.
If you get pieces of dust stuck in your heatsink's thin fins, it creates more blockage which means it's easier to catch more dust in the heatsink. This makes the problem worse, faster. Eventually, no air flows at all, and you end up with heatsink that doesn't work, which means a laptop that doesn't work.
By the way, the Thinkpad R61e uses 1 fan in the left corner. It draws air from the back side and pushes it out the left side. It's not as quiet as the Macbook using 2 slower fans, but I'm confident it will last a long time with no problems. Overall a good design choice given that it's priced between the Compaq and Macbook Pro, and the lower end of the Thinkpads.
The Thinkpad and Macbook both use 2 heatpipes instead of 1.
The Macbook uses them in parallel and go to both heatsinks.
The Thinkpad uses one for the CPU and a separate one for the GPU.
Both designs make sense, but cost more because of the added copper.
The Compaq uses 1 heatpipe through the CPU, the GPU, and the heatsink. This means that less heat can be carried to the heatsink, so everything ends up hotter.
In fact, at a glance, the Thinkpad appears to have 2x the amount of copper as the Compaq, and the Macbook has probably 3x more.
It costs more to have more copper, and even more to have a heatpipe, but it works better.
Overall, the Compaq was cheaper because less effort was put into designing a good laptop, and less expensive components used in manufacturing it.
It was designed to be more easily mass produced and at much lower cost.
It's not going to last as long. It's going to die sooner by going up in flames unless you go above and beyond to take good care of it.
Considering that after cleaning and modifications, it's usable again, I expect to need to take it apart to clean in a year or two again.
Simply putting the intake on the side instead of the bottom would have crossed the line between awful design and mediocre.
So yeah, most laptops use similar parts, but it's not just what you use, but how you use it.
* Another observation: The Thinkpad uses a plastic shell like the Compaq. But the Thinkpad reinforces it with a very strong and lightweight magnesium frame. As part of the keyboard and frame design, the keyboard is perforated in a manner that leads fluids to flow into channels in the frame, and then out drain holes on the bottom of the plastic case. Why?
They understand people tend to kill many laptops by spilling drinks all over the keyboard.
IBM/Lenovo understood early on that being able to be back up and running ASAP is important in business.
They understand that businesses often have an IT department who services machines, and hence have a supply of parts.
So, they designed the Thinkpads with drain holes so that when you do spill your orange juice over the computer, the damage is limited to the keyboard.
All the expensive electronics are saved and reusable.