When Amazon announced it was going to produce a tablet, we weren't surprised. At some point, everyone knew that the company would expand beyond its e-reader base and jump onto the more functional tablet bandwagon. The question was always how far, exactly, Amazon would go in bridging the divide between its popular Kindle and successful tablets like Apple's iPad 2. After using the Kindle Fire for the last week, we can say it's probably not what you were expecting.

Let's start with what the Kindle Fire is not: it isn't an iPad killer. But that doesn't make it a bad product. In fact, that's not even a fair comparison, really. If you've already started reading reviews of the Fire, then you know this is a different beast intended for a different type of customer.

Physically, the Kindle Fire is hardly even comparable to the 10.1" tablets we've reviewed. It's 0.3" thick and weighs 0.89 pounds, making it thicker and heavier than many models with larger screens. The Fire's 7" display gives it a look similar to Research in Motion's smaller PlayBook.
Top to Bottom: Kindle 4th-gen, Kindle Fire, iPad 2, Xoom
Aside from the power button on the bottom of the Fire, Amazon's tablet is otherwise button-free. And while there's a headphone port, there is no dedicated volume control. The speakers are up along the top edge, and the whole tablet is surrounded by a rubberized plastic shell, similar to Toshiba's Thrive. The difference is that Amazon opted for a smooth finish, so it's easier to see fingerprint build-up.
Bottom (Left to Right): Headphone jack, microUSB port, power button
Even compared to 7" Android-based tablets, the Kindle Fire is still a completely different piece of hardware, intended to serve a unique purpose. Notably, it's missing a slew of features, including a GPS, front- and rear-facing cameras, and a microphone. That rules out video conferencing using Skype or mapping out directions to the bar across town. Clearly, when Amazon designed its Fire, it was going for a device more similar to its e-book readers.
| Specifications | Length | Width | Height | Screen Size | Resolution | Aspect Ratio | Weight |
|---|---|---|---|---|---|---|---|
| Amazon Kindle Fire | 7.5" | 4.7" | 0.45" | 7" | 1024x600 | 16:10 | 0.89 lb. |
| Apple iPad 2 (3G) | 9.5" | 7.31" | .34" | 9.7" | 1024x768 | 4:3 | 1.33 lb. |
| Motorola Xoom | 9.8 | 6.6" | .5" | 10.1" | 1280x800 | 16:10 | 1.5 lb. |
| Samsung Galaxy Tab 10.1 | 10.1" | 6.9" | 0.34" | 10.1" | 1280x800 | 16:10 | 1.3 lb. |
This makes sense, of course. The company's priority was never to replace your netbook, or even to give you a jaw-dropping tablet experience. Amazon makes its money by selling products and services, and its Kindle Fire makes it easier to consume both. If you're already a fan of Amazon's offerings, this is a tablet that caters to your base desires.
The Kindle Fire uses the older Android 2.3 kernel (Gingerbread), intended for smartphones. Although Amazon did a great job enhancing Google's generic interface, the Kindle Fire isn't as intuitive to navigate as tablets that leverage Honeycomb (3.x). First off, Gingerbread lacks dedicated navigation buttons. That isn't a problem for smartphones, since they have physical buttons. The Kindle Fire doesn't, though.
Like competing tablets, you have to unlock the Fire's screen to use it. Just slide the orange bar to the left and you're ready to go.
Interestingly, the unlock screen only presents itself in a portrait orientation. With other tablets, the display automatically adapts to reflect the way you're holding them.
Once you get past the lock screen, the accelerometer automatically adjusts orientation, just as you'd expect. However, the layout of Amazon's operating environment is notably different from other tablets. Gone is the icon-filled desktop. Instead, you get a digital bookshelf.
The top tier saves a record of your most recently-used programs, so it functions similarly to Android's multitasking switcher. Selecting an app is as easy as flipping through the stack and double-tapping on an icon.
Shelves below the first row are used for apps designated as "Favorites," though the Facebook icon is actually a URL shortcut to the Web browser, and not its own piece of software.
Amazon divides everything up based on media type: Newsstand, Books, Music, Video, Docs, Apps, and Web. Like other tablets, the search field allows you to quickly locate an app, which is helpful if you have a large library. But it's also useful for searching the Web.
Whenever you navigate away from the main screen, the Kindle Fire displays a row of buttons at the bottom.
- Home button: instantly takes you to home screen
- Back button: move to a previous screen or App
- Menu button: access different viewing modes or additional options for an App
- Search button: instantly takes you to the search screen
Notifications don't pop up like they do in Honeycomb's system tray. Instead, there's a small counter in the upper left-hand corner that logs when you get an email or a download finishes. Meanwhile, the Fire's various settings are accessed by tapping the gear icon in the upper right-hand corner.
The keyboard is generic to Android, similar to Motorola's Xoom. Typing in portrait mode is more difficult, though, because the smaller screen results in smaller keys.
The Kindle name is normally associated with Amazon's e-book readers, which offer a convenient way to carry around a lot of consumable content. The e-ink-based screen isn't for everyone. But it's great for reading text over extended periods. Though the Fire employs a more power-hungry LCD display, it also inherits the Kindle namesake. As such, Amazon makes readability a priority.
You swipe to flip pages, and page turns aren't animated.
Music
Multimedia is what sets the Fire apart from Amazon's e-ink-based products. The Kindle Keyboard and Touch both support MP3 playback, but that isn't their core competency. Low capacity forgettable audio quality mean you'll probably look to products like the Fire for more a more enjoyable experience.
Music app: "Shop this artist" Link
Music app
Amazon uses the stock music player from Android 2.3, which will make it familiar to those of you with a Gingerbread-based smartphone. The company tweaked its interface, though, so you can shop for music within the app. This works flawlessly, provided your ID3 tags are correct.
Video: On Demand
The Kindle Fire excels at video, with one small caveat. Amazon is really using the device to push its streaming Instant Video service. Unfortunately, this isn't free.
If you're a Prime member, you won't have to pay for content tagged as Prime Instant Video. However, not all movies and TV shows fall into this category, which is why you should check out the selection on Amazon before you spend on a Prime membership.
The playback interface is very simple. You can seek within a track, change the volume, rewind 10 seconds, pause, and play. The screenshots may seem a little dark, but that's only because the controls are overlaid on top of the video image. Second, there's a slight black gradient effect to provide better contrast.
Interestingly, all of the video-on-demand (VOD) content is HTML5. On a desktop computer, Amazon streams Flash video. Presumably, this is to save on battery life.
It's only possible to play video from Amazon's VOD service in landscape mode, which suits us just fine.
There is one quirk where flipping the orientation after starting a video results in an upside-down control interface. The only way to fix this is to completely stop playback by hitting the back button and resume playback.
Video: Local Files
Nothing prevents you from playing locally-stored video. However, the Fire only has 5 GiB of user-accessible space, some of which you'll have to set aside for the apps you want to install. Of course, there's also the matter of music and e-books. You might get one or two high-quality movie rips onto the Fire, tops.
Interestingly, there aren't any orientation issues during local video playback.
I haven't experimented much with specific codecs or file extensions. We only use H.264-encoded MP4 video files in the lab, simply because they're compatible across all platforms. With that said, you need to install a program like mVideoPlayer if you want MKV support (see Appendix B).
If you're a movie buff, be aware you can't play any video file larger than 2 GB. Oddly, we encountered a similar problem on HP's TouchPad. It's not clear if there's a link. Both tablets use a FAT32 file system architecture, so the maximum file size should be 4 GB. But, while our 2.8 GB Blu-ray rip is detected, it won't play back.
Amazon's Appstore effectively replaces Android Market. Many news apps are available to correspond with the Kindle Fire, but often times, the apps in Appstore are missing or out of date compared to Android Market.
Why is this the case ? Amazon's Developer FAQ clarifies:
"For your app to work on Kindle Fire, it needs to be compatible with the device's specifications. At a high level, it must be optimized for non-Google Mobile Services (GMS), Android 2.3.4 (Gingerbread), and a 7" screen with a resolution of 1024 x 600. Your manifest should specify support for large screens. Your app cannot require a gyroscope, camera, WAN module, Bluetooth, microphone, GPS, or micro-SD to function. In addition, your app must not be a theme or wallpaper that manipulates the user interface of the device. As with any other app submission to the Amazon Appstore for Android, your app will also need to comply with our Content Guidelines.
This explains the lack of a Skype app, since you need a microphone and camera for VoIP. That doesn't mean you can't use Skype for instant messaging. But unfortunately, Amazon simply won't let you install it.
Sometimes the Kindle Fire uses older apps because newer ones aren't yet certified. For example, the latest version of Flash for Android is 11.1, but the Fire is limited to 10.3. Getting better performance necessitated installing Flash 11.1 manually.
Kindle Fire Comes With Flash 10.3
Unfortunately, getting around this obstacle could involve rooting your device. If you're not familiar with the process, it can render your tablet unusable. However, if you have a second Android device, you can generate an APK and install apps without rooting. But first, you need to enable "Allow Installation of Applications From Unknown Sources" under Settings>Device (see Appendix B).
It's both cumbersome and time consuming to back up and transfer APKs from another tablet. Plus, you can't install applications on the go. That's why I rooted and installed various Google APKs directly onto the Fire, giving me access to all of the Google apps that Amazon chose to strip out: Android Market, Books, Voice, Maps, Google+, Reader, Gmail, Street View, YouTube, and Talk.
Given all of the attention paid to the Fire as a piece of hardware, it's easy to forget that Amazon is primarily a merchant. Naturally, it dedicated lots of effort to developing its Shop app. If you're an Amazon addict, Shop provides a clean and intuitive interface that makes buying stuff on a touchscreen (disturbingly) effortless.
Amazon Silk refers to the Fire's browser and its underlying technology. The idea behind Silk is to offload some processing onto Amazon's EC2 cloud, decreasing the time it takes to render a webpage on a comparatively slow mobile device and reducing overall power consumption. In theory, this should help extend battery life. And while this sounds awesome on paper, it's perhaps not a real benefit when put to actual use.
The problem is in its execution. To begin, Silk doesn't use the cloud to accelerate every webpage. Second, even when it uses the cloud, Silk dynamically determines what parts of the browser subsystems (for instance, networking, HTML, page rendering) to accelerate.

This graph was generated from a debugging script that polled CPU usage on the Kindle Fire. It illustrates the performance difference between processing a webpage locally and using Amazon's cloud.
The CPU workload is evenly distributed during a local test, as the browser requests data and processes it in real-time. When you enable cloud acceleration, the Fire idles for a short period while it waits on the EC2 servers to collect webpage data.
However, in order to counterbalance the time spent idle, Amazon's servers uses the SPDY compression protocol from Google to send information back. This is partly why cloud acceleration should be faster. After receiving the data, though, the Fire still needs to take what it received and generate the page itself. The thing is, what gets compressed must then be decompressed. And that's why CPU usage spikes.

The benefits of cloud acceleration aren't necessarily evident when you look at CPU usage alone; the time it takes to receive data, decompress it, and render differs from one page to another. Generally, cloud acceleration is enabled when there are a lot of HTML elements, seen on sites like cnn.com and our stories. When it does occur, the speed-up isn't really that dramatic.

Overall, power consumption tends to be a wash when you compare a local job to cloud-based acceleration.
It's also possible that I'm not requesting data from a site with a slow connection to my ISP. In that case, the rendering speed could be faster in the cloud, since Amazon has some of the fastest data pipes in the world.

As with most Web browsers, Silk maintains a local cache of data. Amazon doesn't specify how much space it sets aside, but as you browse more sites, Silk clears old data to make sure space is available. With cloud acceleration enabled, Amazon is supposed to prefetch certain linked webpages. However, requesting a linked page not stored in cache turns out to be faster when cloud acceleration is disabled. See Appendix B for instructions on how to disable cloud acceleration.
Aside from our issues with cloud acceleration, Amazon Silk works identically to the Web browsers on every other Android tablet. You can open multiple tabs and switch between desktop and mobile views.
Amazon doesn't make it easy to select and copy text, though. The process is much simpler on Honeycomb-based devices because both options appear above Chrome's address bar.
You see the standard Android pop-up window when you select and hold your finger down on a hyperlink. Straightforward, right? But copying chunks of text remains difficult, since that same pop-up window doesn't appear after a selection.
Many webpages recognize the Android user agent to prevent you from playing Flash video. Silk is no exception, though that's not a problem unless you enjoy sites like Hulu.
Comedy Central also blacklisted Android browsers since our last look at Flash. It's still possible to play few short HTML5-based clips on The Colbert Report, but full episodes are no longer available.
We can play Flash video on CNN, though. The newest version of Flash does make playback noticeably smoother. Interestingly, installing Flash 11.1 on the Kindle Fire breaks VP6 Flash support, which is why you get a blank screen when Flash-based commercials play (you can still hear audio).
CPU Horsepower: Closer to A5 Than Tegra 2
As we’ve mentioned in the past, mobile devices like smartphones and tablets use highly integrated logic referred to as SoCs to minimize physical footprints and power consumption, all the while optimizing for performance and functionality. By putting execution resource, graphics processing, system memory, and several other subsystems in a single ASIC, data transfers can be achieved more efficiently without soldering a bunch of separate chips onto a PCB. Incidentally, the same SoC term applies to modern desktop processors like Intel's Sandy Bridge- and AMD's Bulldozer-based chips, which combine cores, cache, memory controllers, and other capabilities.
The Kindle Fire uses TI's OMAP (Open Multimedia Application Platform) 4430 SoC. We haven't had as much experience with this specific piece of hardware, but the underlying technology is similar to the more familiar Tegra 2 and A5 in that all three employ dual-core Cortex-A9s clocked at 1 GHz.
| SoC | Apple A4 | Apple A5 | Nvidia Tegra 2 | TI OMAP 4430 |
|---|---|---|---|---|
| Processor | 1 GHz ARM Cortex-A8 (single-core) | 1 GHz ARM Cortex-A9 (dual-core) | 1 GHz ARM Cortex-A9 (dual-core) | 1 GHz ARM Cortex-A9 (dual-core) |
| Memory | 256 MB 333 MHz LP-DDR (single-channel) | 512 MB 1066 MHz LP-DDR2 (dual-channel) | 1 GB 667 MHz LP-DDR2 (single-channel) | 512 MB 400 MHz LP-DDR (dual-channel) |
| Graphics | PowerVR SGX535 (single-core) | PowerVR SGX545MP2 (dual-core) | ULP GeForce (single-core) | PowerVR SGX540 (single-core) |
| L1 Cache (Instruction/Data) | 32 KB / 32 KB | 32 KB / 32 KB | 32 KB / 32 KB | 32 KB / 32 KB |
| L2 Cache | 640 KB | 1 MB | 1 MB | 1 MB |
Given the common CPU architecture, it shouldn't be a surprise that Linpack generates the same score on Amazon's Kindle Fire as it does on our Tegra 2-based Xoom.

Even so, the OMAP 4430 has more in common with Apple's A5 than it does with the Tegra 2. Why is this? Apple and TI both use A9s with an ARM SIMD engine, better known as NEON. It's capable of decoding MP3s on an ARM CPU running as slow as 10 MHz, which provides added benefits in power savings. Why don't all SoCs feature the Advanced SIMD extension? Architecturally, it imposes a physically larger and more costly SoC.
GPU: Better Than A4, Worse Than A5
On the graphics side, the OMAP 4430 employs Imagination Technology's PowerVR SGX 540. This should be familiar because it's derived from the same architecture as the GPUs found in Apple's A4 and A5. The key difference is in the shaders.
| GPU Subsystem (System-on-Chip) | PowerVR SGX 535 (Apple A4) | PowerVR SGX 540 (OMAP 4430) | PowerVR SGX 543 (Apple A5) |
|---|---|---|---|
| SIMD | USSE | USSE | USSE2 |
| Pipelines | 2 | 4 | 4 |
| TMUs | 2 | 2 | 2 |
| Bus Width (in bits) | 64 | 64 | 64 |
| Triangle rate @ 200 MHz | 14 MTriangles/s | 28 MTriangles/s | 35 MTriangles/s |
The SGX 543 in the A5 includes four USSE2 (Universal Scalable Shader Engine 2.0) pipes. In comparison, the SGX 540 has the same number of pipes but uses the older USSE design. The SGX 535 hails from the same GPU generation as the SGX 540, but it only has two USSE pipes.
While the architecture is interesting, performance data is what we're after, which is why we're turning to GLBenchmark.

The OMAP 4430 falls expectedly between the A4 and A5. Though it's probably shocking to see the SGX 540 outperform Nvidia's ULP GeForce by such a large margin, remember that GLBenchmark tests at a device's native resolution. On our Tegra 2-based tablets, that's always 1280x800. Meanwhile, the Kindle Fire only has to do its work at 1024x600.

We can get normalize for that resolution issue by looking at the off-screen tests set to 720p. Based on those results, we see the SGX 540 core performing similarly as Tegra 2's ULP GeForce.

No matter how Tegra 2 performs, Nvidia is to be commended for its effort in advocating game development on mobile hardware. And let's draw a distinction between the masses of graphically-unimpressive titles and the ones that do legitimately cool stuff with 3D.
Unfortunately, the games most likely to sport truly impressive graphics are often exclusive to Tegra 2-based devices. That's a real problem if you're on a different hardware platform. It's even worse for the Kindle Fire because Amazon's Appstore offers an even poorer selection of games.
There is a technical reason for this limitation, beyond Nvidia's habit of swinging its marketing around like a baseball bat. Software developers writing for Tegra 2 often use Nvidia's proprietary 3D libraries. As such their games just won't work on Android-based devices powered by TI or Qualcomm SoCs.
As an experiment though, I extracted the APKs for Riptide GP, Sprinkle, and Shadowgun from our Motorola Xoom and installed them on the Kindle Fire. Note that Riptide and Sprinkle started as Tegra 2-exclusive games on Android, but were eventually ported to iOS.
Kindle Fire: Shadowgun Crashes
Unfortunately, Shadogun crashes immediately after we select game difficulty.
Riptide is playable without any problems, but screen shots always end up with artifacts.
Kindle Fire: Riptide GP, Screenshots With Artifacts
Xoom: Riptide GP, Artifact-Free Screenshot
We haven't featured Sprinkle in any of our hardware reviews, but it's similar to Angry Birds. The difference is that you use a water cannon to put out fires that threaten villagers. While the concept sounds cheesy, the water effects are downright impressive, making the game more enjoyable. On the Kindle Fire, we still get tearing effects in screen shots.
Kindle Fire: Sprinkle, Screenshot With Artifacts
Xoom: Sprinkle, Artifact-Free Screenshot
Game play is smooth, but as you can see in the video below, water effects are incorrectly rendered. Instead of one continuous stream, we get a lot of individual bubbles.
The mobile game compatibility landscape looks a lot like the desktop scene did 15 years ago, when titles were more inherently tied to a compatible 3D accelerator. Things won't really change, though, until game developers and SoC vendors all agree to abide by a common gaming framework and driver architecture.
If you're planning to root and install games on your Fire, make note of our experience with these three titles. Some will work. Some won't. And others simply don't look quite right.
Space on the Kindle After Installing All Our Apps
Though there's not a lot of user-accessible space on the Kindle Fire, it's a real pain to fill it up over USB.
| USB File Transfer 2.8 GB H.264 encoded MP4 Movie | Avg. Transfer Rate | Time |
|---|---|---|
| Amazon Kindle Fire (OS Level File Transfer) | 2.76 MB/s | 17:14.615 |
| Apple iPad 2 (iTunes) | 19.19 MB/s | 02:29.090 |
| Motorola Xoom (OS Level File Transfer) | 13.18 MB/s | 03:36.990 |
The process is excruciatingly slow, with a top sequential speed somewhere around 2.7 MB/s. If you're moving small files, expect initial speeds around 1.2 MB/s. Meanwhile, other tablets that support USB 2.0 frequently hit average speeds above 10 MB/s.
Samsung's eMMC NAND In Kindle Fire
Hardware isn't the problem. Amazon employs a Samsung 8 GB KLM8G2FEJA eMMC NAND package. You find the same product in competing tablets, like Acer's 8 GB A100. Motorola employs a 32 GB eMMC NAND chip from Toshiba with similar specs. And yet, transfers are much faster on the Xoom.
The zippy transfer rate on the iPad 2 in the table above shouldn't come as a surprise. Apple is the only major tablet manufacturer to use vanilla MLC NAND, which is found in the zippy SSDs we all know and love. But that also means the A5 contains extra logic to add block management and ECC.
Since Tegra 2 and OMAP lack the same circuitry as Apple's A5, nearly all Android-based tablets use a simpler storage implementation called eMMC, which embeds block management and ECC onto the NAND itself. The difference is highlighted in the slide above.
Since everything is managed at the NAND level, the operating system doesn't have to bother issuing commands like secure erase or TRIM. The MMC controller in the storage device handles all of that. However, this also means that eMMC NAND is blind to much of what the operating system is doing. The result is a significant amount of performance overhead.
| Amazon Kindle Fire | Apple iPad 2 | Motorola Xoom | |
|---|---|---|---|
| NAND Chip | Samsung KLM8G2FEJA | Toshiba TH58NVG7D2FLA89 | Toshiba THGBM2G8D8FBAIB |
| NAND Bus | eMMC v4.41 | Toggle 1.0 | eMMC v4.4 |
| NAND Bus Speed | 104 MB/s | 133 MB/s | 104 MB/s |
Of course, the difference between eMMC and regular NAND isn't limited to block management. The bus interface is also different. Whereas Toggle Mode 1.0 is limited to 133 MB/s, for instance, eMMC tops out at 104 MB/s. There's a new revision of eMMC that bumps speeds up to 200 MB/s, but it's currently too new and too expensive for tablet manufactures to implement.
Xoom: Uses Media Transfer Protocol
It's not clear if there's a way to address the Kindle Fire's low transfer speeds through firmware. Other Android tablet vendors implement Microsoft's Media Transfer Protocol, whereas Amazon chooses the more generic USB Mass Storage Class (MSC) driver. That's good news for Mac users, since you don't need a special program to transfer files.
Kindle Fire: Appears As Generic USB Device In Mac OS X
It's possible that the problem is with Amazon's USB MSC implementation. The only way to transfer files is to put the Fire in Mass Storage mode preventing you from using the tablet at the same time. However, it also suggests that Mass Storage mode is a hosted layer above the operating system.
RIM got around this issue with its Blackberry line by implementing a pass-through mode for transfers. It's likely that Amazon will have to do something similar in order to speed up USB performance. Currently, transferring files to your Kindle Fire over your home network using Astro (along with its SMB module) is likely faster than using USB.
The easiest way to identify a device's display panel is to take it apart. Though we've done this in the past, it's not necessary to be so invasive. A microscope is just as telling, which is why we keep one on hand in the lab.
Technically, we're supposed to calibrate our microscope for scale, but I decided to include two pictures instead to give you an idea of how small these subpixels really are.
This first picture is a sliver of a stained onion root cell and a single human hair on top of a stage micrometer slide (used in biological sciences to make measurements). The little dot in the corner has a diameter of 0.07 mm. That comes out to 70 μm.
This is the same dot superimposed over the Amazon Shop app icon on the home screen of the Kindle Fire.
At the microscopic level, the subpixel structure comes into focus. Given our previous experience with tablets, this is an IPS panel from LG, a conclusion confirmed by our friends over at iFixit.

The Kindle Fire's 7" LG IPS panel offers up excellent brightness close to 450 nits, but gamut performance is fairly low, at 48% of the AdobeRGB 1998 spec.
At 6900 K, color temperature is close to the standard 6500 K. However, many colors appear dull due to a relatively low gamma. For background information on our benchmarks, see Appendix A.








Despite the Kindle Fire's smaller 7" screen, battery life falls relatively close to Acer's 10.1" Iconia A500 Tab. However, our browsing test requires some explanation, because we prevent the browser from caching webpage data. As such, this benchmark reflects a usage scenario where new webpages are continuously loaded. If you only browse a handful of sites, the Fire should last a little longer.
The Fire's recharge time is pretty zippy. You can go from completely drained to a full charge in just under three hours. However, this assumes that you're using the AC adapter. It's possible to charge over USB, but it's a slower process (close to nine hours). See Appendix B for information on the restrictions imposed while charging over USB.



Our input lag test tends to be on the optimistic side, because I only measure the time it takes for the first letter of a word to appear on a screen. So, this score really reflects baseline performance. However, input lag tends to vary within a 100 ms range, which is why lag can be much higher than what we're showing here, especially if you can type well on a tablet.
Generally, input lag on the Fire hovers around 300 ms, which should be fine for most people. If you're typing fast, lag can increase to levels sufficiently high to be noticeable. Occasionally, high input lag also manifests itself when the Fire has to wake from standby or when you're trying to perform multiple commands in quick succession.
Given the relatively long time it takes to launch a browser, any performance issue is likely more related to software than hardware. The OMAP 4430 boasts as much processing power as Nvidia's Tegra 2, and we've seen plenty of tablets based on that SoC offering better scores. As it stands, the customized Amazon environment based on Android 2.3 benchmarks less impressively than Honeycomb.


Earlier this year, the lab overhauled the process of evaluating Wi-Fi performance. For background information, check out page 10 of Acer Iconia Tab A500: A Tablet With Honeycomb 3.1. Moving forward, I'm going to focus mostly on throughput, which is why I've elected to exclude response time scores. Generally, these two metrics go hand in hand, so I feel that it's somewhat redundant to publish both.
Two scenarios are being tested here:
- Five feet, line-of-sight: The wireless device is set five feet from the router without any obstructions.
- 20 feet, no line-of-sight: The wireless device is set 20 feet from the router and there are three drywall obstructions in our testing environment that reflect the possible degradation you might see in an indoor environment.
All devices idle for two minutes before testing in order to prevent power-saving rules in the OS from affecting wireless performance.



Context. That's really important when you're looking at the Kindle Fire. Is it an iPad killer? No, but it really wasn't trying to be.
In many ways, the Fire still an iPad competitor, but only because both devices are technically tablets. It's only natural that you'd look at both as contenders in the same ring. In reality, though, the choice is more akin to comparing a truck to a sedan. Both are automotive vehicles, but each has its different niche.
Without detracting from Apple's innovation, the iPad works better as a pseudo-netbook replacement. If you want to browse the Web, check email, play some games, listen to music, and type notes without the hassle of flipping out a keyboard, the iPad works great.
Amazon is really trying to push a different kind of product. While other companies sell their own branded hardware, Amazon is, first and foremost, a merchant. It's in the business of selling products made by others, which is why the Fire is more of a front-end that enables you to consume more music, video, and e-books (from Amazon, of course).
| Tablet Pricing | 8 GB | 16 GB | 32 GB | 64 GB |
|---|---|---|---|---|
| Apple iPad 2 (Wi-Fi) | - | $499 | $599 | $699 |
| Amazon Kindle Fire (Wi-Fi) | $199 | - | - | - |
| Asus Eee Pad Transformer (Wi-Fi) | - | $399 | $469 | - |
| Motorola Xoom (Wi-Fi) | - | - | $499 | - |
| Samsung Galaxy Tab 10.1 (Wi-Fi) | - | $499 | $599 | - |
In a sea of tablet options, the Fire's biggest advantage is its low price tag. Interestingly, Amazon is basically breaking even on its manufacturing costs by selling at $199 (source: iSuppli), but that's probably a good thing for the company. Amazon is following in the path paved by Nintendo, Sony, and Microsoft. Sell the console cheap and make money on the stuff your users buy for it.
If you're an addict for Amazon's various offerings, this tablet is going to be an easy favorite. But don't expect the same experience you'd get from an iPad 2 or Eee Pad Transformer. It's not simply a $200 version of those pricier products. If that's the way you approach tablet shopping, the Kindle Fire's allure will wear off quickly and you'll end up with a piece of technology that sits next to your computer collecting dust.
Amazon's first real tablet is far from completely polished. Battery life is nothing to write home about, and input lag is higher than what we've seen from other tablets. Transfer speeds over USB are downright poor, and there are restrictions on charging while connected to a system. Furthermore, the display's color gamut is barely worth mentioning, and the cloud acceleration aspect of Amazon Silk could use some tuning.
The Kindle Fire gets points for being an incredibly durable tablet. Braver souls have already tried scratching the screen with their keys and dropping the device from two or three feet without a scratch (check out the BlogKindle Youtube videos).
To be fair, though, we've found plenty to criticize on every tablet that has passed through our lab. But if you're willing to opt in to an Amazon's Prime membership or eager to purchase a number of e-books, this could be the tablet for which you've been waiting. For everyone else, we have a review coming up on a tablet that hits a great price point and doesn't sacrifice as many features. Keep an eye out for that!
Display Analysis
Before we start our rather rigorous benchmarking process, we disable dynamic brightness because it prevents us from getting an accurate and reproducible measurement of the display’s potential. Second, brightness is set to the highest value. If you don't use the same settings, your color gamut is going to look smaller than what our benchmarks show.
Second, even though mobile operating systems don't honor ICC color profiles, native color management does occur at the hardware level. When a GPU sends 10 different hues of blue to an LCD only capable of displaying three, the subpixels display the closest matching color. So, in a way, smartphones and tablets behave as if they’re using relative colorimetric rendering. For more information, read Tom's Hardware Benchmarks Inkjet Printer Paper!
With respect to gamma, understand that it doesn’t affect black or white performance, only midtones. If gamma is set too high, the midtones appear dark. If it's set too low, they're pale. Adobe, Apple, and Microsoft all recommend a gamma of 2.2. It's an arbitrary value carried over from the NTSC standard, but it was originally chosen because it allows colors to appear more natural in slightly dim environments.
Battery Life & Recharge Time
Testing a tablet’s battery life tends to be highly variable unless you control the entire experience from beginning to end. Cumulatively, touch gestures don’t have a great impact on battery life. The biggest factors are CPU/GPU processing, screen brightness, volume, and Wi-Fi use. In order to accurately measure battery life, I coded a script that automatically plays MP3s at 50% volume while browsing different Wikipedia pages every 12 minutes. This benchmark is probably overkill, but it gives you an idea of a worst-case scenario.
Very few sites go through the trouble of benchmarking recharge time. However, in my view, it's as important as battery life. Though, it's not necessarily desirable to have a fast recharging time. Ideally, you want a nice slow charge so that your battery lasts more than a few hundred charges. Rapid charge times keep you away from the wall socket longer, but in the long run it cuts down on the health of the battery. Usually, the rate of charge starts to slow down somewhere in the 80% to 95% range, which is why the charging time from 0% to 10% is faster than 90% to 100%.
Real-World Performance
Early on, we discovered how difficult it is to benchmark tablets.
Benchmarking responsiveness with a camera is the easiest approach. Of course, normal cameras don't cut it, since they only shoot at 29 FPS. That's unacceptable if you're trying to measure precise time differences. Going the stopwatch route is no better, due to human-introduced errors. As a result, we're using a 1000 FPS high-speed camera to measure performance. Since one frame equals one millisecond, it’s possible to measure timing with a high degree of accuracy.
Boot and launch times aren't as important as input lag in our view. However, we're defining input lag in a slightly different way from the manner it’s used in discussing display technology. Our focus is more on real-world usability. As such, we define input lag "as the time between pressing a key and text appearing on-screen." This tells you how fast a tablet is registering an action. Ideally, you want low input lag so that you don't feel the tablet stuttering as you type or click on buttons. The average college student has a reaction time of 200 milliseconds for visual stimuli, so that's really the target for which we look.
USB Debugging, Screenshots, & Rooting
Amazon doesn't include drivers that support the native Android Debug Bridge for Android's SDK, which means you need to perform a manual modification for Windows to recognize the tablet (a necessary step if you want to take screen shots on it).
- Turn on "Allow Installation of Applications From Unknown Sources" in Kindle Fire
- In Windows, put following device descriptions into the [Google.NTx86] and [Google.NTamd64] sections of extras\google\usb_driverandroid_winusb.inf:
;Kindle Fire
%SingleAdbInterface% = USB_Install, USB\VID_1949&PID_0006
%CompositeAdbInterface% = USB_Install, USB\VID_1949&PID_0006&MI_01 - Add 0x1949 into the .android/adb_usb.ini file in the Home directory by using following command from the shell prompt.
In Windows:
echo 0x1949 >> %HOMEPATH%.androidadb_usb.ini
In OS X:
echo "0x1949" >> $HOME/.android/adb_usb.ini
- In Windows: Restart. Plug in the tablet, and when driver installation fails, select "Have Disk" under "Device Manager." Select the driver named "Composite ADB Interface."
Disable Cloud Acceleration for Amazon Silk
- Open up the Web browser on Kindle Fire.
- Click on menu button and go to settings.
- Scroll down and uncheck "Accelerate page loading"
USB Charging
The Kindle Fire will only charge when you plug it into a computer's USB port if it's mounted as a storage device. The tablet will not charge if you are using it.
Install Android Marketplace (Warning: Requires Rooting):Link
Generate APK using Secondary Android Device: Link
APK Download from Our Lab:
- Adobe Flash 11.1 - Download
- Astro 2.1.8 - Download
- Firefox 2.0 - Download
- Meridian 2.1.5 - Download
- mVideoPlayer 2.9.1 - Download
- Skype 2.5 - Download
You must first enable "Allow Installation of Applications From Unknown Sources" to install these APKs. Install Easy Installer from the Amazon Appstore or follow the Backup menu options from Astro for easier app management.






























































