As expected, Amazon has updated its 7-inch Fire HD tablet, and added two new Fire HDX models. The new Fire HD is lighter than its predecessor, makes gains in the processor department and gets treated to a brand new operating system. The two HDX flavors both feature Qualcomm's Snapdragon 800 quad-core processor, have sharper displays than their stablemates and are available with up to 64 GB of storage.

The all-new Kindle Fire HDX

The Kindle Fire HDX has a 7-inch, 1920 x 1200 resolution display at 323 ppi, which Amazon says also benefits from 100 percent sRGB color accuracy, dynamic image contrast and should be bright enough for comfortable indoor or outdoor viewing. Within its 7.3 x 5 x 0.35 in (186 x 128 x 9 mm) housing beats a quad-core Snapdragon 800 processor running at 2.2 GHz, with 2 GB of RAM, either 16, 32 or 64 GB of storage and an Adreno 330 graphics engine that promises up to four times better performance than the previous Fire HD models.

The HDX has integrated dual-band, dual antenna (MIMO and HT40) 802.11n Wi-Fi, with the option to include 4G LTE connectivity (via AT&T or Verizon). Bluetooth with support for A2DP has been included for listening to audio through wireless headphones and the tablet also sports stereo speakers with Dolby Digital Plus audio for virtual 5.1 surround sound.

It runs Amazon's Android-based Fire OS version 3.0, or Mojito for short, which benefits from a number of platform and performance tweaks, including improved touch latency, enhanced email and browsing, improved screen reader, and native Android app compatibility. The latest OS also adds new features like the Mayday button, enterprise features and carousel and grid navigation.

Accessed via the Quick Settings menu, the Mayday button opens the door to live 24/7 technical support on the HDX itself. The service is free to use, and Amazon is aiming to get users connected to an expert within 15 seconds, who will then walk them through problem resolution.

Other new feature highlights include the ability to download from the Prime Instant Video streaming service, upgraded X-Ray for Music that now includes lyrics with songs, and Second Screen, which can wirelessly send the onscreen image to a compatible big screen TV.

Amazon also states that the new HDX has been made enterprise-ready, boasting support for software encryption, Kerberos Intranet, secure Wi-Fi connections, native SCEP and VPN client integration, and wireless printing.

Physical connectivity comes in the shape of a 3.5 mm jack for audio, and a micro-USB 2.0 port for connection to a computer or for charging the battery. Charge time is reported to take less than six hours, and users can expect up to 11 hours of mixed use between charges.

Completing the specs are an HD webcam to the front, an ambient light sensor, accelerometer and gyro, and assisted GPS (available on 4G models only).

The 7-inch Fire HDX weighs in at 10.7 oz (303 g) for the Wi-Fi only version, or 11 oz (311 g) for the 4G flavor, and prices start at US$229. Nifty Origami magnetic covers have also been announced that can be folded to support portrait or landscape viewing.

The Kindle Fire HDX 8.9

The new Fire HDX 8.9 unsurprisingly has an 8.9-inch display, with 2560 x 1600 resolution at 339 ppi. This model also packs a Snapdragon 800 2.2 GHz quad-core processor, 2 GB of RAM and Adreno 330 graphics. It comes in the same storage choices as its smaller HDX brother, and the wireless connectivity options, audio capabilities, and included sensors are also the same.

This 9.1 x 6.2 x 0.31 in (231 x 158 x 7.8 mm) model does promise an extra hour of mixed usage between charges, and charge time via micro-USB has been cut to under five hours using the supplied charger. It also features an 8 MP camera at the back with LED flash, and wide aperture f/2.2 lens and electronic image stabilization, as well as the front-facing 720p webcam.

The Fire HDX 8.9 weighs a little more than its smaller sibling, at 13.2 oz (374 g) for the Wi-Fi model, or 13.5 oz (384 g) if you want 4G. Prices start at $379.

The new Kindle Fire HD

Amazon has also refreshed its 7-inch Kindle Fire HD tablet and given it a $139 starting price. The new model has the same 1280 x 800 resolution (at 216 ppi) display as its ancestor, but gains a 1.5 GHz dual-core processor supported by 1 GB of system memory, and comes in either 8 or 16 GB versions.

It's lighter, too, at 12.2 oz (345 g), and has slightly different dimensions (7.5 x 5 x 0.42 in/191 x 128 x 10.6 mm). Users get dual-band, single antenna 802.11n Wi-Fi, Bluetooth with A2DP support, integrated stereo speakers with Dolby Digital Plus, and a 10 hour battery life between six hour charges.

Parents gifting young ones with the new Fire HD will doubtless be relieved to find more parental controls on offer (such as choosing appropriate content and setting time limits) via Kindle FreeTime.

The Fire HD is up for pre-order from today, with shipping due to start from the beginning of October.

Amazon has opted not to include its Fire HD 8.9 model in this round of upgrades and new releases. This version is still available for $269.

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