Making Sense of Tablet Specs: A Technology Cheat Sheet

This is why spec sheets get an F when it comes to educating consumers. To all but the wonkiest of gadget geek, they are a mix of jargon and numbers that may convey granular device details, but require a Rosetta Stone to decipher.

To make matters worse, the manufacturers love to tout the specs in marketing materials, claiming their products are the first dual-core this or most advanced Android that. Really? Your tablet runs Android with a custom skin and has a dual-core processor? That's great, but what does it mean?

For back to school season, the experts at TabletPCReview are in the teaching mood. But since we are not fans of boring tech jargon, consider this crash course more of a cheat sheet than dry textbook education. Here are what arguably amount to the three most important tablet tech specs, broken down in plain English.

Operating System (OS):
If you get a new iPad, it will be running the latest version of iOS. As of the time of this writing, the same is true for the PlayBook and TouchPad, as Apple, RIM and HP all only have one tablet in their lineups. A Windows 7 tablet might be running one of a handful of versions of the operating system, but the basic look, feel, and features will remain consistent.

With Android tablets, it's a different story due to fragmentation. There are close to a dozen Android tablets worth considering, with new models hitting store shelves each month. Of the tablets available for back to school, most run Android Honeycomb version 3.1 or higher, with Honeycomb being Google's tablet OS. Three, the Samsung Galaxy Tab, HTC Flyer, and HTC EVO View 4G, run Android Gingerbread (2.3), which was designed with small-screen smartphones in mind, though has been adapted for the seven-inch tablets.?

Sometimes you might see something like this, which was taken from HTC's EVO View 4G/HTC Flyer spec sheet:

Android 2.3 (Gingerbread) with HTC Sense

In this case, "HTC Sense" is HTC's own custom-designed user interface (UI) applied to Android 2.3. Sometimes called a skin, it is basically HTC's tweaks to Android. Google is cool with developers lightly tweaking Android with small features like different keyboards and proprietary widgets. It helps manufacturers distinguish their tablets from the competitions'. Another popular UI is TouchWiz, which is found on the Samsung Galaxy tablets. This is why you might find a Swype keyboard preloaded on the Samsung Galaxy Tab and not the LG G-Slate.

Display:
The display size is arguably a more important spec than the operating system. There is no right size for a tablet, only preference, and the difference in size between a seven-inch tablet like the PlayBook and the 10.1-inch Motorola Xoom is stark. The PlayBook will easily fit in a purse or even cargo pants pocket, while the Xoom (and iPad) are more suited for backpacks.

Next to size, display resolution is also an important number. So let's check that out and break down the iPad 2's display spec from the Apple website:

9.7-inch (diagonal) LED-backlit glossy widescreen Multi-Touch display with IPS technology 1024-by-768-pixel resolution at 132 pixels per inch (ppi)

So the Apple iPad 2 has a display that measures 9.7-inches from corner to corner and is backlit by light-emitting diode technology. All tablets screen sizes are measured corner to corner, and just about all are LED backlit because LED lights can be bright, can easily slot into thin tablets, and don't consumer much power.

IPS stands for in-plane switching, which is a display technology that enables wide viewing angles. Sometimes, you might also see TFT, TFT-LCD or super TFT. TFT stands for thin film transistor, and it's the technology that improves the image and contrast of LCD panels, making them suitable for tablets. Do you remember the LCD televisions from a few years back? They had a very limited viewing angle (the picture was tough to see if not viewed from straight on) and the blacks were washed out, like a faded black t-shirt. Today's tablet LCDs are much easier on the eyes.

"Multi-touch" simply means the tablet can register more than one touch input at a time. Why is that important? Well, without it, you wouldn't be able to pinch to zoom or use a two-finger swipe/scroll.

Next to the display size, the pixel resolution is the second most important number. "1024-by-768" refers to the number of pixels along the long side of the iPad by the number along the short side. Together, the pixels from both sides form a grid, and on any give square inch, there are 132 pixels per inch (ppi). PPI is very important and it's based on the resolution and screen size. If you increase the iPad's display by a few inches but keep the same resolution, the ppi goes down (larger display + same number of pixels = bigger pixels = less pixels per square inch). Shrink the iPad, and the ppi goes up.

The iPad 2's 132 ppi is close to the current standard for tablets. The Motorola Xoom has 150 ppi, as does the Galaxy Tab 10.1. Most expect the next generation tablets to have higher resolutions and more pixels per inch, but there may be limits. Many experts agree that the human eye cannot discern more than 300 pixels per inch, which is close to what the iPhone 4 is rocking with its 326 ppi.

There is also a loose standard associated with resolution as it applies to aspect ratio, so you might see WXGA or something similar listed as the resolution. WXGA stands for wide extended graphics array and it basically indicates a resolution at or near 1280 x 800 with a 16:10 aspect ratio. A 16:10 aspect ratio simply means that for every 10 pixels of length, there are 16 pixels of width. This also applies to home theater, where you might read about an HDTV with a 16:9 aspect ratio, which is also referred to as "widescreen" because it is more rectangular than square.

Processor:
Sometimes referred to as a chip, chipset, or CPU, the tablet processor can tell us a lot about the tablet. Unfortunately, processor architecture is tough to grasp, so let?s stick with the basics.

The type of chip powering most tablets (and smartphones) is called an ARM processor, and it's great because it supplies just enough power while not overly straining the battery.

The company that holds the right to the ARM processor design doesn't actually make any ARM chips. Instead, the company, ARM Holdings, licenses the rights to Samsung, Qualcomm, Texas Instruments, NVIDIA, and others to make ARM chips, with Intel being the notable exception.

So if you buy a tablet tomorrow, chances are it will have an ARM chip, even though the specific ARM chip may be a Qualcomm Snapdragon or NVIDIA Tegra 2.

Let's take a look at the Samsung Galaxy Tab 10.1 processor spec:

1GHz dual-core NVIDIA Tegra 2 processor

The 1GHz figure refers to the clock speed in gigahertz. In this particular case, the Galaxy Tab 10.1 processor can execute 1 billion cycles, or instructions, per second. A processor with a clock speed of 800MHz (megahertz) can process 800 million cycles per second. The higher the clock speed, the faster the computer, in general.

Things get a bit complex when it comes to cores. A single-core processor has one unit on the circuit die doing all the work and executing all the instructions. A dual-core processor has two units on the same size circuit die working in tandem, each dealing with a separate set of instructions, or threads. This is also sometimes called parallel processing or chip-level multiprocessing (CLM). As a result, a dual-core processor can easily handle a bit more work and juggle a few more processes without much delay, making it better at multitasking.

It's important to note that one dual-core processor is not directly comparable to two single-core processors, because elements like cache and software design play a major role in determining overall performance. However, the dual-core design is preferable to stuffing two single-core processors in a device because the dual-core processor takes up less space, consumes less power, and emits less heat.

Think of the advantages dual-core offers over single-core this way: if you are washing dishes with one arm tied behind your back (single-core) and the phone rings, you have to stop washing dishes to pick up the receiver. With two hands (dual-core), you can continue to wash dishes with one arm while the other reaches over to pick up the handset. Things might slow down a bit, but you should be able to continue both tasks with relative ease.

Dual-core processors are powering today's top tablets, but quad-core processors are right around the corner. So what can you do with four cores? Well, the four-armed dishwasher can also answer the phone, dry the dishes, and put them away. Tablet makers will probably use the quad-core chips to help power ultra-high resolution displays with 300+ ppi.

OS, display, and processor are just three of the many specs listed in the technical details. Connectivity is also a major consideration (see our breakdown on 4G technology), as is battery type, memory, sensors, graphics processor unit, and input/outputs, to name a few.

But there will be time for those later, maybe after the midterms. Right now, study this cheat sheet hard, and if you can't commit it to memory, stash it somewhere you can sneak peeks during the next tablet pop quiz.

Thrive for Back to School
A productive pupil gets good grades, but even the most studious of student?needs a subtle distraction to keep them awake during a boring lecture. For our money, no tablet offers a better combination of productive function and time-killing fun than the Toshiba Thrive Honeycomb tablet, the TabletPCReview choice for back to school.

Interested in what other products the TechnologyGuide experts picked for Back to School?

Back to School Buyer's Guide 2011

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