TFT VS LED backlit MacBook

1. LED is better. Search Google for the differences.
2. Because they can. Why not?
3. Whether it's better or not depends on your definition of "better."

Smaller is better because it can be stored in more places. With many products, smaller also means lighter. Less weight means the object is easier to move around, and more portable. Who doesn't want a machine that's easier to move around?

The polycarbonate MacBooks have proven prone to developing stress fractures on the topcase near the trackpad. The aluminum unibody MacBooks don't have that problem, but lack a Firewire port. It comes down to what matters most to the user.

~Lyssa

Typically, "thinner" means a lighter notebook. And I'd rather see them go this route instead of squeezing the thing down to the size of a netbook.

Just for clarity, a TFT (Thin Film Transistor liquid crystal display) display can be backlit with a CCFL (Cold Cathode Florescent Lamp) or it can be backlit with an array of LEDs (Light Emitting Diodes).

Therefor, it does not make sense to say TFT VS LED. The new MacBook and the old both use a TFT display as do virtually all color LCD displays. The new MacBook uses LEDs for a backlight whereas the old MacBook uses a single CCFL for a backlight. They are both of course a TFT type of Liquid Crystal Display.

One advantage of the LED type is that the LED should never go dim. This is not true of the CCFL. They start to get dimmer with the first use and ultimately burn out. Most CCFLs have a life expectancy of around 25,000 to 35,000 hours before they will only produce 80% of the light intensity that they did when new.

Like watching the hour hand on a clock you never see it move but it does. The same is true of the brightness of your standard CCFL based laptop. They get dimmer with usage, you just don't notice it. It is very measurable though if you use a light meter.

I would definitely prefer an LED backlit LCD for this reason.

Gregory Mcintire wrote:
One advantage of the LED type is that the LED should never go dim. This is not true of the CCFL. They start to get dimmer with the first use and ultimately burn out. Most CCFLs have a life expectancy of around 25,000 to 35,000 hours before they will only produce 80% of the light intensity that they did when new.

LEDs do dim over time - albeit slowly - with an average useful life much longer than most other light sources. Dimming is not that apparent when you've got little things like indicator lights. However - arrays have benefits compared to single sources. You can make do with a few dead LEDs while a burned out single bulb is useless. That's one of the benefits of LED arrays in traffic lights. They produce more light, use far less power (enough to make battery backup practical), and still work if one or more LEDs are gone.

http://www.colorkinetics.com/support/whitepapers/LEDLifetime.pdf

This is the crux of effectively defining LED source lifetime. The failure of an LED is observed primarily as a reduction in light output over time, as opposed to a sudden and complete failure. The technical term for this is lumen depreciation. So, if there is no direct measurable failure, how do we determine at what point the light output is still useful or not? One way to decide end-of-life is when the light output reaches a defined percentage of the initial light output. So, although it is 'not quite dead yet', the overall light output is perceptibly below its light output in infancy. Various measures and percentages have been proposed, but 50% and 70% of initial lumen output are generally accepted values.

http://www.philipslumileds.com/pdfs/WP12.pdf

LED light sources, on the other hand, do not tend to fail catastrophically. Instead, the light output degrades gradually over time. The useful operating lifetime of a power LED is extremely long, and often longer than the lifetime of the product in which it is embedded. In a large installation, depending on the mission life of the fixture, the effect of this fading over time may be to reduce the overall light output to a level below the specified minimum. However, as relamping is so infrequent, the total cost of ownership is reduced.

I do have experience with an older CCFL backlight iBook G3. It is getting rather dim now after about four years of use.

I always measure the light intensity of the display of laptops and PDAs when I get them. I use them for many hours per day. I have found that my last iBook (CCFL) for instance, after 2 years of use, dimmed to the point that it was like setting the little brightness such that at full bright it was the same as 4 clicks less than full bright was when it was brand new.

On the other hand my PDAs do not show any measurable loss of light intensity from brand new to the day I sell them or otherwise quit using them. They have all had White LEDs as a backlight.

I have bought a number of Powerbooks on eBay cheap because their CCFL was either too dim to be usable any more or was completely burned out. I just replace the CCFL for a cost of $15 and they are as bright as brand new.

But in only a few months that super bright display that you had when it was brand new is about one or two clicks dimmer if you use it as much as I do.

In fact, this is a good place to point out that using a "screen saver" on a laptop not only does not save the LCD (modern LCDs do not develop screen burn like a CRT in the first place) but it wears out the CCFL backlight. If you want to save your LCD screen do not use a screen saver, turn OFF the backlight.

I contend that the reason the LEDs dim at all over time is that they are overpowered in many applications. Some of those applications are as tail lights in cars and trucks. The manufacturers are trying to get the maximum brightness possible with as few LEDs as possible so they over power them to a point that is still deemed as satisfactory with regard to life expectancy.

Therefore, if you keep the brightness turned down to something less than full on your laptop that uses an LED source for backlight, I contend it will never dim a measurable amount for the life of the computer. At least this is born out with my PDAs. The same is not true with a CCFL when used at a lower than full setting. It still gets dim with usage. Note: by 'measurable' I mean with a light meter, not with a subjective opinion as observed.

Mauricette wrote:
Believe it or not, there are large part of customers care about what they can do in Macbooks rather than how thinner the Macbooks can be.

I tend to disagree. As a newcomer to the mac world I soon discovered a lot of mac evangelists are really concerned with aesthetics - first and foremost. Just watching people swoon and slobber over their macs on Youtube actually made me think twice before I got mine. There is a niche market for sleek and pretty and Apple found it.

As for me, I tend to take a utilitarian approach to things so if thinner means it's easier to lug around without sacrificing performance then I'm all for it.

But to your point... the thicker and heavier macbook white sales seem to be hanging in there and I envision a revolt of sorts when the time comes for Apple to discontinue them.

I went to an Apple store, money in hand, and looked at and played with a new aluminum MacBook. I left the store with my money. I was not impressed with the looks or the performance. I guess it was slower than mine due to mine having a 7200 RPM drive maybe.

To each his own I guess.

My MacBook came with a 5400 RPM hard drive. After about 2 years I wanted more speed so I put in a 7200 RPM drive and it is much faster and it uses slightly LESS electrical power so therefore I consider my 7200 RPM drive to be better than my 5400 RPM drive. Oh, the 7200 RPM drive has more than twice the storage capacity!

Depending on the age of the drive... a new 5400 RPM drive can perform similarly to an older 7200 RPM drive. A new 7200 RPM drive will almost certainly perform better than a two year old 5400 RPM one. The issue comes down to how much data they pack into a given space (aerial density). They can pack much more data into the same space on a platter today than they could a few years ago. Think of it this way... If you think of the drive platter as a tape instead and you unroll a foot of it. You have two of them... one can store 100MB per inch and the other can store 10MB per inch. With that scenario, if they were both running at the same RPM, the one storing 100MB per inch would move ten times more data in the same time. Not because it is faster, but because there is more data in the same space. Now when you expand this out to a hard drive... a 5400 RPM drive can perform just as well as a faster 7200 RPM drive with a lower aerial density. All things being equal, if you take a current 7200 RPM drive and 5400 RPM drive with identical densities, the 7200 RPM would be faster.

So far as making the machines thinner... while Apple's OS is really what makes their machines better, their design is what turns peoples heads. Many people turn to Macs because they look "cool". Once they start using the OS, they find out that is the real advantage. You could make the same argument about netbooks. It would be easy to say why make a computer which is so short on features and processing power. The simple answer is that there is a market for them. There is even a market for the MacBook Air. They made major sacrifices on that machine in terms of connectivity and performance... but the "wow" factor was enough for many... and just like with netbooks, everyone does not need a super powerful machine, so the Air is more than suitable for lots of people.